diff --git a/src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorLanguageServerBenchmarkBase.cs b/src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorLanguageServerBenchmarkBase.cs
index 77b6d3f0c3..f4c9db8e9a 100644
--- a/src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorLanguageServerBenchmarkBase.cs
+++ b/src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorLanguageServerBenchmarkBase.cs
@@ -76,7 +76,7 @@ public class RazorLanguageServerBenchmarkBase : ProjectSnapshotManagerBenchmarkB
                 updater.ProjectAdded(hostProject);
                 var tagHelpers = CommonResources.LegacyTagHelpers;
                 var projectWorkspaceState = ProjectWorkspaceState.Create(tagHelpers, CodeAnalysis.CSharp.LanguageVersion.CSharp11);
-                updater.ProjectChanged(hostProject, projectWorkspaceState);
+                updater.ProjectWorkspaceStateChanged(hostProject.Key, projectWorkspaceState);
                 updater.DocumentAdded(hostProject.Key, hostDocument, textLoader);
             },
             CancellationToken.None);
diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/ProjectSystem/RazorProjectService.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/ProjectSystem/RazorProjectService.cs
index 872d1c2a8d..25f498d721 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/ProjectSystem/RazorProjectService.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/ProjectSystem/RazorProjectService.cs
@@ -369,21 +369,34 @@ internal partial class RazorProjectService : IRazorProjectService, IRazorProject
                     _logger.LogInformation($"Updating project '{project.Key}' TagHelpers ({projectWorkspaceState.TagHelpers.Length}) and C# Language Version ({projectWorkspaceState.CSharpLanguageVersion}).");
                 }
 
+                updater.ProjectWorkspaceStateChanged(project.Key, projectWorkspaceState);
+
                 var currentConfiguration = project.Configuration;
                 var currentRootNamespace = project.RootNamespace;
+                if (currentConfiguration.ConfigurationName == configuration?.ConfigurationName &&
+                    currentRootNamespace == rootNamespace)
+                {
+                    _logger.LogTrace($"Updating project '{project.Key}'. The project is already using configuration '{configuration.ConfigurationName}' and root namespace '{rootNamespace}'.");
+                    return;
+                }
+
                 if (configuration is null)
                 {
                     configuration = FallbackRazorConfiguration.Latest;
                     _logger.LogInformation($"Updating project '{project.Key}' to use the latest configuration ('{configuration.ConfigurationName}')'.");
                 }
-                else if (currentConfiguration.Equals(configuration) &&
-                    currentRootNamespace == rootNamespace)
+                else if (currentConfiguration.ConfigurationName != configuration.ConfigurationName)
                 {
-                    _logger.LogTrace($"Updating project '{project.Key}'. The project is already using configuration '{configuration.ConfigurationName}' and root namespace '{rootNamespace}'.");
+                    _logger.LogInformation($"Updating project '{project.Key}' to Razor configuration '{configuration.ConfigurationName}' with language version '{configuration.LanguageVersion}'.");
+                }
+
+                if (currentRootNamespace != rootNamespace)
+                {
+                    _logger.LogInformation($"Updating project '{project.Key}''s root namespace to '{rootNamespace}'.");
                 }
 
                 var hostProject = new HostProject(project.FilePath, project.IntermediateOutputPath, configuration, rootNamespace, displayName);
-                updater.ProjectChanged(hostProject, projectWorkspaceState);
+                updater.ProjectConfigurationChanged(hostProject);
             },
             cancellationToken);
     }
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DocumentState.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DocumentState.cs
index c3b47291e3..7c09f3bfc4 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DocumentState.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DocumentState.cs
@@ -150,6 +150,15 @@ internal partial class DocumentState
         return false;
     }
 
+    public virtual DocumentState WithConfigurationChange()
+    {
+        var state = new DocumentState(HostDocument, Version + 1, _textAndVersion, _textLoader);
+
+        // Do not cache computed state
+
+        return state;
+    }
+
     public virtual DocumentState WithImportsChange()
     {
         var state = new DocumentState(HostDocument, Version + 1, _textAndVersion, _textLoader);
@@ -160,7 +169,7 @@ internal partial class DocumentState
         return state;
     }
 
-    public virtual DocumentState WithProjectChange()
+    public virtual DocumentState WithProjectWorkspaceStateChange()
     {
         var state = new DocumentState(HostDocument, Version + 1, _textAndVersion, _textLoader);
 
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectDifference.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectDifference.cs
index 20d383dd8e..f309380a70 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectDifference.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectDifference.cs
@@ -8,9 +8,10 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem;
 [Flags]
 internal enum ProjectDifference
 {
-    None = 1 << 0,
-    ConfigurationChanged = 1 << 1,
-    DocumentAdded = 1 << 2,
-    DocumentRemoved = 1 << 3,
-    DocumentChanged = 1 << 4,
+    None = 0,
+    ConfigurationChanged = 1,
+    ProjectWorkspaceStateChanged = 2,
+    DocumentAdded = 4,
+    DocumentRemoved = 8,
+    DocumentChanged = 16,
 }
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectSnapshotManager.Updater.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectSnapshotManager.Updater.cs
index 57c016bfa5..12ce627279 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectSnapshotManager.Updater.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectSnapshotManager.Updater.cs
@@ -50,8 +50,11 @@ internal partial class ProjectSnapshotManager
         public void ProjectRemoved(ProjectKey projectKey)
             => instance.ProjectRemoved(projectKey);
 
-        public void ProjectChanged(HostProject project, ProjectWorkspaceState projectWorkspaceState)
-            => instance.ProjectChanged(project, projectWorkspaceState);
+        public void ProjectConfigurationChanged(HostProject project)
+            => instance.ProjectConfigurationChanged(project);
+
+        public void ProjectWorkspaceStateChanged(ProjectKey projectKey, ProjectWorkspaceState projectWorkspaceState)
+            => instance.ProjectWorkspaceStateChanged(projectKey, projectWorkspaceState);
 
         public void SolutionOpened()
             => instance.SolutionOpened();
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectSnapshotManager.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectSnapshotManager.cs
index 9b7eba4a3a..1436c39a5d 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectSnapshotManager.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectSnapshotManager.cs
@@ -306,7 +306,7 @@ internal partial class ProjectSnapshotManager : IProjectSnapshotManager, IDispos
         }
     }
 
-    private void ProjectChanged(HostProject hostProject, ProjectWorkspaceState projectWorkspaceState)
+    private void ProjectConfigurationChanged(HostProject hostProject)
     {
         if (_initialized)
         {
@@ -316,7 +316,25 @@ internal partial class ProjectSnapshotManager : IProjectSnapshotManager, IDispos
         if (TryUpdate(
             hostProject.Key,
             documentFilePath: null,
-            new ProjectChangeAction(hostProject, projectWorkspaceState),
+            new HostProjectUpdatedAction(hostProject),
+            out var oldSnapshot,
+            out var newSnapshot))
+        {
+            NotifyListeners(oldSnapshot, newSnapshot, documentFilePath: null, ProjectChangeKind.ProjectChanged);
+        }
+    }
+
+    private void ProjectWorkspaceStateChanged(ProjectKey projectKey, ProjectWorkspaceState projectWorkspaceState)
+    {
+        if (_initialized)
+        {
+            _dispatcher.AssertRunningOnDispatcher();
+        }
+
+        if (TryUpdate(
+            projectKey,
+            documentFilePath: null,
+            new ProjectWorkspaceStateChangedAction(projectWorkspaceState),
             out var oldSnapshot,
             out var newSnapshot))
         {
@@ -573,8 +591,11 @@ internal partial class ProjectSnapshotManager : IProjectSnapshotManager, IDispos
                     }
                 }
 
-            case ProjectChangeAction(var hostProject, var workspaceState):
-                return new Entry(originalEntry.State.WithHostProjectAndWorkspaceState(hostProject, workspaceState));
+            case ProjectWorkspaceStateChangedAction(var workspaceState):
+                return new Entry(originalEntry.State.WithProjectWorkspaceState(workspaceState));
+
+            case HostProjectUpdatedAction(var hostProject):
+                return new Entry(originalEntry.State.WithHostProject(hostProject));
 
             default:
                 throw new InvalidOperationException($"Unexpected action type {action.GetType()}");
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectState.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectState.cs
index 7d89c69336..37a5189547 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectState.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectState.cs
@@ -21,6 +21,12 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem;
 // Internal tracker for DefaultProjectSnapshot
 internal class ProjectState
 {
+    private const ProjectDifference ClearConfigurationVersionMask = ProjectDifference.ConfigurationChanged;
+
+    private const ProjectDifference ClearProjectWorkspaceStateVersionMask =
+        ProjectDifference.ConfigurationChanged |
+        ProjectDifference.ProjectWorkspaceStateChanged;
+
     private const ProjectDifference ClearDocumentCollectionVersionMask =
         ProjectDifference.ConfigurationChanged |
         ProjectDifference.DocumentAdded |
@@ -91,9 +97,7 @@ internal class ProjectState
             DocumentCollectionVersion = Version;
         }
 
-        if (older._projectEngine != null &&
-            HostProject.Configuration == older.HostProject.Configuration &&
-            CSharpLanguageVersion == older.CSharpLanguageVersion)
+        if ((difference & ClearConfigurationVersionMask) == 0 && older._projectEngine != null)
         {
             // Optimistically cache the RazorProjectEngine.
             _projectEngine = older.ProjectEngine;
@@ -104,7 +108,9 @@ internal class ProjectState
             ConfigurationVersion = Version;
         }
 
-        if (ProjectWorkspaceState.Equals(older.ProjectWorkspaceState))
+        if ((difference & ClearProjectWorkspaceStateVersionMask) == 0 ||
+            ProjectWorkspaceState == older.ProjectWorkspaceState ||
+            ProjectWorkspaceState.Equals(older.ProjectWorkspaceState))
         {
             ProjectWorkspaceStateVersion = older.ProjectWorkspaceStateVersion;
         }
@@ -112,6 +118,14 @@ internal class ProjectState
         {
             ProjectWorkspaceStateVersion = Version;
         }
+
+        if ((difference & ClearProjectWorkspaceStateVersionMask) != 0 &&
+            CSharpLanguageVersion != older.CSharpLanguageVersion)
+        {
+            // C# language version changed. This impacts the ProjectEngine, reset it.
+            _projectEngine = null;
+            ConfigurationVersion = Version;
+        }
     }
 
     // Internal set for testing.
@@ -303,16 +317,20 @@ internal class ProjectState
         return state;
     }
 
-    public ProjectState WithHostProjectAndWorkspaceState(HostProject hostProject, ProjectWorkspaceState projectWorkspaceState)
+    public ProjectState WithHostProject(HostProject hostProject)
     {
+        if (hostProject is null)
+        {
+            throw new ArgumentNullException(nameof(hostProject));
+        }
+
         if (HostProject.Configuration.Equals(hostProject.Configuration) &&
-            HostProject.RootNamespace == hostProject.RootNamespace &&
-            ProjectWorkspaceState.Equals(projectWorkspaceState))
+            HostProject.RootNamespace == hostProject.RootNamespace)
         {
             return this;
         }
 
-        var documents = Documents.ToImmutableDictionary(kvp => kvp.Key, kvp => kvp.Value.WithProjectChange(), FilePathNormalizingComparer.Instance);
+        var documents = Documents.ToImmutableDictionary(kvp => kvp.Key, kvp => kvp.Value.WithConfigurationChange(), FilePathNormalizingComparer.Instance);
 
         // If the host project has changed then we need to recompute the imports map
         var importsToRelatedDocuments = s_emptyImportsToRelatedDocuments;
@@ -323,7 +341,25 @@ internal class ProjectState
             importsToRelatedDocuments = AddToImportsToRelatedDocuments(importsToRelatedDocuments, document.Value.HostDocument.FilePath, importTargetPaths);
         }
 
-        var state = new ProjectState(this, ProjectDifference.ConfigurationChanged, hostProject, projectWorkspaceState, documents, importsToRelatedDocuments);
+        var state = new ProjectState(this, ProjectDifference.ConfigurationChanged, hostProject, ProjectWorkspaceState, documents, importsToRelatedDocuments);
+        return state;
+    }
+
+    public ProjectState WithProjectWorkspaceState(ProjectWorkspaceState projectWorkspaceState)
+    {
+        if (ProjectWorkspaceState == projectWorkspaceState)
+        {
+            return this;
+        }
+
+        if (ProjectWorkspaceState.Equals(projectWorkspaceState))
+        {
+            return this;
+        }
+
+        var difference = ProjectDifference.ProjectWorkspaceStateChanged;
+        var documents = Documents.ToImmutableDictionary(kvp => kvp.Key, kvp => kvp.Value.WithProjectWorkspaceStateChange(), FilePathNormalizingComparer.Instance);
+        var state = new ProjectState(this, difference, HostProject, projectWorkspaceState, documents, ImportsToRelatedDocuments);
         return state;
     }
 
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/UpdateProjectAction.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/UpdateProjectAction.cs
index 6ecc957629..bc6e89a202 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/UpdateProjectAction.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/UpdateProjectAction.cs
@@ -30,4 +30,6 @@ internal record ProjectAddedAction(HostProject HostProject) : IUpdateProjectActi
 
 internal record ProjectRemovedAction(ProjectKey ProjectKey) : IUpdateProjectAction;
 
-internal record ProjectChangeAction(HostProject HostProject, ProjectWorkspaceState WorkspaceState) : IUpdateProjectAction;
+internal record HostProjectUpdatedAction(HostProject HostProject) : IUpdateProjectAction;
+
+internal record ProjectWorkspaceStateChangedAction(ProjectWorkspaceState WorkspaceState) : IUpdateProjectAction;
diff --git a/src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/LiveShare/Guest/ProjectSnapshotSynchronizationService.cs b/src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/LiveShare/Guest/ProjectSnapshotSynchronizationService.cs
index 8d0cf1b08e..295ec7ec6c 100644
--- a/src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/LiveShare/Guest/ProjectSnapshotSynchronizationService.cs
+++ b/src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/LiveShare/Guest/ProjectSnapshotSynchronizationService.cs
@@ -85,7 +85,7 @@ internal class ProjectSnapshotSynchronizationService(
 
                     if (state.projectWorkspaceState != null)
                     {
-                        updater.ProjectChanged(state.hostProject, state.projectWorkspaceState);
+                        updater.ProjectWorkspaceStateChanged(state.hostProject.Key, state.projectWorkspaceState);
                     }
                 },
                 state: (hostProject, projectWorkspaceState: args.Newer.ProjectWorkspaceState),
@@ -108,16 +108,31 @@ internal class ProjectSnapshotSynchronizationService(
         }
         else if (args.Kind == ProjectProxyChangeKind.ProjectChanged)
         {
-            if (!args.Older!.Configuration.Equals(args.Newer!.Configuration) ||
-                !args.Older.ProjectWorkspaceState.Equals(args.Newer.ProjectWorkspaceState))
+            if (!args.Older!.Configuration.Equals(args.Newer!.Configuration))
             {
                 var guestPath = ResolveGuestPath(args.Newer.FilePath);
                 var guestIntermediateOutputPath = ResolveGuestPath(args.Newer.IntermediateOutputPath);
                 var hostProject = new HostProject(guestPath, guestIntermediateOutputPath, args.Newer.Configuration, args.Newer.RootNamespace);
-                var projectWorkspaceState = args.Newer.ProjectWorkspaceState;
                 await _projectManager.UpdateAsync(
-                    static (updater, state) => updater.ProjectChanged(state.hostProject, state.projectWorkspaceState),
-                    state: (hostProject, projectWorkspaceState),
+                    static (updater, hostProject) => updater.ProjectConfigurationChanged(hostProject),
+                    state: hostProject,
+                    CancellationToken.None);
+            }
+            else if (args.Older.ProjectWorkspaceState != args.Newer.ProjectWorkspaceState ||
+                args.Older.ProjectWorkspaceState?.Equals(args.Newer.ProjectWorkspaceState) == false)
+            {
+                var guestPath = ResolveGuestPath(args.Newer.FilePath);
+                await _projectManager.UpdateAsync(
+                    static (updater, state) =>
+                    {
+                        var projectKeys = updater.GetAllProjectKeys(state.guestPath);
+
+                        foreach (var projectKey in projectKeys)
+                        {
+                            updater.ProjectWorkspaceStateChanged(projectKey, state.projectWorkspaceState);
+                        }
+                    },
+                    state: (guestPath, projectWorkspaceState: args.Newer.ProjectWorkspaceState),
                     CancellationToken.None);
             }
         }
@@ -137,7 +152,7 @@ internal class ProjectSnapshotSynchronizationService(
 
                     if (state.projectWorkspaceState is not null)
                     {
-                        updater.ProjectChanged(state.hostProject, state.projectWorkspaceState);
+                        updater.ProjectWorkspaceStateChanged(state.hostProject.Key, state.projectWorkspaceState);
                     }
                 },
                 state: (hostProject, projectWorkspaceState: projectHandle.ProjectWorkspaceState),
diff --git a/src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/ProjectSystem/WindowsRazorProjectHostBase.cs b/src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/ProjectSystem/WindowsRazorProjectHostBase.cs
index 74ee53de74..de2e60c007 100644
--- a/src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/ProjectSystem/WindowsRazorProjectHostBase.cs
+++ b/src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/ProjectSystem/WindowsRazorProjectHostBase.cs
@@ -265,7 +265,7 @@ internal abstract partial class WindowsRazorProjectHostBase : OnceInitializedOnc
 
     protected static void UpdateProject(ProjectSnapshotManager.Updater updater, HostProject project)
     {
-        if (!updater.TryGetLoadedProject(project.Key, out var current))
+        if (!updater.TryGetLoadedProject(project.Key, out _))
         {
             // Just in case we somehow got in a state where VS didn't tell us that solution close was finished, lets just
             // ensure we're going to actually do something with the new project that we've just been told about.
@@ -275,7 +275,7 @@ internal abstract partial class WindowsRazorProjectHostBase : OnceInitializedOnc
         }
         else
         {
-            updater.ProjectChanged(project, current.ProjectWorkspaceState);
+            updater.ProjectConfigurationChanged(project);
         }
     }
 
diff --git a/src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/ProjectWorkspaceStateGenerator.cs b/src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/ProjectWorkspaceStateGenerator.cs
index 3a4f66b2c1..e6b29390c6 100644
--- a/src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/ProjectWorkspaceStateGenerator.cs
+++ b/src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/ProjectWorkspaceStateGenerator.cs
@@ -157,18 +157,17 @@ internal sealed partial class ProjectWorkspaceStateGenerator(
                 .UpdateAsync(
                     static (updater, state) =>
                     {
-                        var (projectSnapshot, workspaceState, logger, cancellationToken) = state;
+                        var (projectKey, workspaceState, logger, cancellationToken) = state;
 
                         if (cancellationToken.IsCancellationRequested)
                         {
                             return;
                         }
 
-                        logger.LogTrace($"Updating project with {workspaceState.TagHelpers.Length} tag helper(s) for '{projectSnapshot.Key}'");
-                        var hostProject = new HostProject(projectSnapshot.FilePath, projectSnapshot.IntermediateOutputPath, projectSnapshot.Configuration, projectSnapshot.RootNamespace);
-                        updater.ProjectChanged(hostProject, workspaceState);
+                        logger.LogTrace($"Updating project with {workspaceState.TagHelpers.Length} tag helper(s) for '{projectKey}'");
+                        updater.ProjectWorkspaceStateChanged(projectKey, workspaceState);
                     },
-                    state: (projectSnapshot, workspaceState, _logger, cancellationToken),
+                    state: (projectKey, workspaceState, _logger, cancellationToken),
                     cancellationToken)
                 .ConfigureAwait(false);
         }
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeDocumentReferenceHolderTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeDocumentReferenceHolderTest.cs
index 7a6a69eff7..7662dfbf0f 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeDocumentReferenceHolderTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeDocumentReferenceHolderTest.cs
@@ -135,7 +135,7 @@ public class CodeDocumentReferenceHolderTest(ITestOutputHelper testOutput) : Lan
         // Act
         await _projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(s_hostProject with { Configuration = RazorConfiguration.Default, RootNamespace = "NewRootNamespace" }, documentSnapshot.Project.ProjectWorkspaceState);
+            updater.ProjectConfigurationChanged(s_hostProject with { Configuration = RazorConfiguration.Default, RootNamespace = "NewRootNamespace" });
         });
 
         PerformFullGC();
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/DocumentPresentation/TextDocumentUriPresentationEndpointTests.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/DocumentPresentation/TextDocumentUriPresentationEndpointTests.cs
index 691576244d..ffdff50874 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/DocumentPresentation/TextDocumentUriPresentationEndpointTests.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/DocumentPresentation/TextDocumentUriPresentationEndpointTests.cs
@@ -46,7 +46,7 @@ public class TextDocumentUriPresentationEndpointTests(ITestOutputHelper testOutp
 
         await projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(hostProject, ProjectWorkspaceState.Create([builder.Build()]));
+            updater.ProjectWorkspaceStateChanged(hostProject.Key, ProjectWorkspaceState.Create([builder.Build()]));
         });
 
         var uri = new Uri(hostDocument1.FilePath);
@@ -106,7 +106,7 @@ public class TextDocumentUriPresentationEndpointTests(ITestOutputHelper testOutp
 
         await projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(hostProject, ProjectWorkspaceState.Create([builder.Build()]));
+            updater.ProjectWorkspaceStateChanged(hostProject.Key, ProjectWorkspaceState.Create([builder.Build()]));
         });
 
         var uri = new Uri(hostDocument1.FilePath);
@@ -177,7 +177,7 @@ public class TextDocumentUriPresentationEndpointTests(ITestOutputHelper testOutp
 
         await projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(hostProject, ProjectWorkspaceState.Create([builder.Build()]));
+            updater.ProjectWorkspaceStateChanged(hostProject.Key, ProjectWorkspaceState.Create([builder.Build()]));
         });
 
         var uri = new Uri(hostDocument1.FilePath);
@@ -332,7 +332,7 @@ public class TextDocumentUriPresentationEndpointTests(ITestOutputHelper testOutp
 
         await projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(hostProject, ProjectWorkspaceState.Create([builder.Build()]));
+            updater.ProjectWorkspaceStateChanged(hostProject.Key, ProjectWorkspaceState.Create([builder.Build()]));
         });
 
         var uri = new Uri(hostDocument1.FilePath);
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/OpenDocumentGeneratorTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/OpenDocumentGeneratorTest.cs
index 77827f12d7..7c05c89c15 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/OpenDocumentGeneratorTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/OpenDocumentGeneratorTest.cs
@@ -142,7 +142,8 @@ public class OpenDocumentGeneratorTest(ITestOutputHelper testOutput) : LanguageS
             updater.DocumentAdded(_hostProject1.Key, _documents[0], _documents[0].CreateEmptyTextLoader());
 
             // Act
-            updater.ProjectChanged(_hostProject1, ProjectWorkspaceState.Create(LanguageVersion.CSharp8));
+            updater.ProjectWorkspaceStateChanged(_hostProject1.Key,
+                ProjectWorkspaceState.Create(LanguageVersion.CSharp8));
         });
 
         // Assert
@@ -165,7 +166,8 @@ public class OpenDocumentGeneratorTest(ITestOutputHelper testOutput) : LanguageS
             updater.DocumentOpened(_hostProject1.Key, _documents[0].FilePath, SourceText.From(string.Empty));
 
             // Act
-            updater.ProjectChanged(_hostProject1, ProjectWorkspaceState.Create(LanguageVersion.CSharp8));
+            updater.ProjectWorkspaceStateChanged(_hostProject1.Key,
+                ProjectWorkspaceState.Create(LanguageVersion.CSharp8));
         });
 
         // Assert
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Refactoring/RenameEndpointTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Refactoring/RenameEndpointTest.cs
index 1c06d64b97..4c78d3dd3d 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Refactoring/RenameEndpointTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Refactoring/RenameEndpointTest.cs
@@ -656,11 +656,10 @@ public class RenameEndpointTest(ITestOutputHelper testOutput) : LanguageServerTe
 
         var projectKey1 = await projectService.GetTestAccessor().AddProjectAsync(
             s_projectFilePath1, s_intermediateOutputPath1, RazorConfiguration.Default, RootNamespace1, displayName: null, DisposalToken);
-        var hostProject1 = new HostProject(s_indexFilePath1, s_intermediateOutputPath1, RazorConfiguration.Default, RootNamespace1, displayName: null);
 
         await projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(hostProject1, ProjectWorkspaceState.Create(tagHelpers));
+            updater.ProjectWorkspaceStateChanged(projectKey1, ProjectWorkspaceState.Create(tagHelpers));
         });
 
         await projectService.AddDocumentToPotentialProjectsAsync(s_componentFilePath1, DisposalToken);
@@ -679,11 +678,10 @@ public class RenameEndpointTest(ITestOutputHelper testOutput) : LanguageServerTe
 
         var projectKey2 = await projectService.GetTestAccessor().AddProjectAsync(
             s_projectFilePath2, s_intermediateOutputPath2, RazorConfiguration.Default, RootNamespace2, displayName: null, DisposalToken);
-        var hostProject2 = new HostProject(s_projectFilePath2, s_intermediateOutputPath2, RazorConfiguration.Default, RootNamespace2, displayName: null);
 
         await projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(hostProject2, ProjectWorkspaceState.Create(tagHelpers));
+            updater.ProjectWorkspaceStateChanged(projectKey2, ProjectWorkspaceState.Create(tagHelpers));
         });
 
         await projectService.AddDocumentToPotentialProjectsAsync(s_componentFilePath3, DisposalToken);
diff --git a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DocumentStateTest.cs b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DocumentStateTest.cs
index 8a0de5c43c..2632887a2e 100644
--- a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DocumentStateTest.cs
+++ b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DocumentStateTest.cs
@@ -63,14 +63,14 @@ public class DocumentStateTest : ToolingTestBase
     }
 
     [Fact]
-    public void DocumentState_WithProjectChange_CachesSnapshotText()
+    public void DocumentState_WithConfigurationChange_CachesSnapshotText()
     {
         // Arrange
         var original = DocumentState.Create(_hostDocument, DocumentState.EmptyLoader)
             .WithText(_text, VersionStamp.Create());
 
         // Act
-        var state = original.WithProjectChange();
+        var state = original.WithConfigurationChange();
 
         // Assert
         Assert.True(state.TryGetText(out _));
@@ -78,7 +78,7 @@ public class DocumentStateTest : ToolingTestBase
     }
 
     [Fact]
-    public async Task DocumentState_WithProjectChange_CachesLoadedText()
+    public async Task DocumentState_WithConfigurationChange_CachesLoadedText()
     {
         // Arrange
         var original = DocumentState.Create(_hostDocument, DocumentState.EmptyLoader)
@@ -87,7 +87,7 @@ public class DocumentStateTest : ToolingTestBase
         await original.GetTextAsync(DisposalToken);
 
         // Act
-        var state = original.WithProjectChange();
+        var state = original.WithConfigurationChange();
 
         // Assert
         Assert.True(state.TryGetText(out _));
@@ -125,4 +125,36 @@ public class DocumentStateTest : ToolingTestBase
         Assert.True(state.TryGetText(out _));
         Assert.True(state.TryGetTextVersion(out _));
     }
+
+    [Fact]
+    public void DocumentState_WithProjectWorkspaceStateChange_CachesSnapshotText()
+    {
+        // Arrange
+        var original = DocumentState.Create(_hostDocument, DocumentState.EmptyLoader)
+            .WithText(_text, VersionStamp.Create());
+
+        // Act
+        var state = original.WithProjectWorkspaceStateChange();
+
+        // Assert
+        Assert.True(state.TryGetText(out _));
+        Assert.True(state.TryGetTextVersion(out _));
+    }
+
+    [Fact]
+    public async Task DocumentState_WithProjectWorkspaceStateChange_CachesLoadedText()
+    {
+        // Arrange
+        var original = DocumentState.Create(_hostDocument, DocumentState.EmptyLoader)
+            .WithTextLoader(_textLoader);
+
+        await original.GetTextAsync(DisposalToken);
+
+        // Act
+        var state = original.WithProjectWorkspaceStateChange();
+
+        // Assert
+        Assert.True(state.TryGetText(out _));
+        Assert.True(state.TryGetTextVersion(out _));
+    }
 }
diff --git a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateGeneratedOutputTest.cs b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateGeneratedOutputTest.cs
index 1fce00bb94..7dd40de184 100644
--- a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateGeneratedOutputTest.cs
+++ b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateGeneratedOutputTest.cs
@@ -154,7 +154,7 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
         var changed = ProjectWorkspaceState.Default;
 
         // Act
-        var state = original.WithHostProjectAndWorkspaceState(original.HostProject, changed);
+        var state = original.WithProjectWorkspaceState(changed);
 
         // Assert
         var (actualOutput, actualInputVersion) = await GetOutputAsync(state, _hostDocument, DisposalToken);
@@ -175,7 +175,7 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
         var changed = ProjectWorkspaceState.Create(_someTagHelpers);
 
         // Act
-        var state = original.WithHostProjectAndWorkspaceState(original.HostProject, changed);
+        var state = original.WithProjectWorkspaceState(changed);
 
         // Assert
         var (actualOutput, actualInputVersion) = await GetOutputAsync(state, _hostDocument, DisposalToken);
@@ -199,7 +199,7 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
         var (originalOutput, originalInputVersion) = await GetOutputAsync(original, _hostDocument, DisposalToken);
 
         // Act
-        var state = original.WithHostProjectAndWorkspaceState(original.HostProject, changedWorkspaceState);
+        var state = original.WithProjectWorkspaceState(changedWorkspaceState);
 
         // Assert
         var (actualOutput, actualInputVersion) = await GetOutputAsync(state, _hostDocument, DisposalToken);
@@ -219,7 +219,7 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
         var (originalOutput, originalInputVersion) = await GetOutputAsync(original, _hostDocument, DisposalToken);
 
         // Act
-        var state = original.WithHostProjectAndWorkspaceState(_hostProjectWithConfigurationChange, original.ProjectWorkspaceState);
+        var state = original.WithHostProject(_hostProjectWithConfigurationChange);
 
         // Assert
         var (actualOutput, actualInputVersion) = await GetOutputAsync(state, _hostDocument, DisposalToken);
diff --git a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateTest.cs b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateTest.cs
index e88073b55a..f1c3eb75ef 100644
--- a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateTest.cs
+++ b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateTest.cs
@@ -529,7 +529,7 @@ public class ProjectStateTest : WorkspaceTestBase
     }
 
     [Fact]
-    public void ProjectState_WithHostProjectAndWorkspaceState_ConfigurationChange_UpdatesConfigurationState()
+    public void ProjectState_WithHostProject_ConfigurationChange_UpdatesConfigurationState()
     {
         // Arrange
         var original = ProjectState.Create(ProjectEngineFactoryProvider, LanguageServerFeatureOptions, _hostProject, _projectWorkspaceState)
@@ -541,7 +541,7 @@ public class ProjectStateTest : WorkspaceTestBase
         var originalProjectWorkspaceStateVersion = original.ConfigurationVersion;
 
         // Act
-        var state = original.WithHostProjectAndWorkspaceState(_hostProjectWithConfigurationChange, _projectWorkspaceState);
+        var state = original.WithHostProject(_hostProjectWithConfigurationChange);
 
         // Assert
         Assert.NotEqual(original.Version, state.Version);
@@ -567,7 +567,7 @@ public class ProjectStateTest : WorkspaceTestBase
     }
 
     [Fact]
-    public void ProjectState_WithHostProjectAndWorkspaceState_RootNamespaceChange_UpdatesConfigurationState()
+    public void ProjectState_WithHostProject_RootNamespaceChange_UpdatesConfigurationState()
     {
         // Arrange
         var original = ProjectState.Create(ProjectEngineFactoryProvider, LanguageServerFeatureOptions, _hostProject, _projectWorkspaceState)
@@ -580,14 +580,14 @@ public class ProjectStateTest : WorkspaceTestBase
         _ = original.ConfigurationVersion;
 
         // Act
-        var state = original.WithHostProjectAndWorkspaceState(hostProjectWithRootNamespaceChange, _projectWorkspaceState);
+        var state = original.WithHostProject(hostProjectWithRootNamespaceChange);
 
         // Assert
         Assert.NotSame(original, state);
     }
 
     [Fact]
-    public void ProjectState_WithHostProjectAndWorkspaceState_NoConfigurationChange_Noops()
+    public void ProjectState_WithHostProject_NoConfigurationChange_Noops()
     {
         // Arrange
         var original = ProjectState.Create(ProjectEngineFactoryProvider, LanguageServerFeatureOptions, _hostProject, _projectWorkspaceState)
@@ -598,14 +598,14 @@ public class ProjectStateTest : WorkspaceTestBase
         _ = original.ProjectWorkspaceStateVersion;
 
         // Act
-        var state = original.WithHostProjectAndWorkspaceState(_hostProject, _projectWorkspaceState);
+        var state = original.WithHostProject(_hostProject);
 
         // Assert
         Assert.Same(original, state);
     }
 
     [Fact]
-    public void ProjectState_WithHostProjectAndWorkspaceState_CallsConfigurationChangeOnDocumentState()
+    public void ProjectState_WithHostProject_CallsConfigurationChangeOnDocumentState()
     {
         // Arrange
         var callCount = 0;
@@ -618,7 +618,7 @@ public class ProjectStateTest : WorkspaceTestBase
         original.Documents = documents.ToImmutable();
 
         // Act
-        var state = original.WithHostProjectAndWorkspaceState(_hostProjectWithConfigurationChange, _projectWorkspaceState);
+        var state = original.WithHostProject(_hostProjectWithConfigurationChange);
 
         // Assert
         Assert.NotEqual(original.Version, state.Version);
@@ -627,14 +627,14 @@ public class ProjectStateTest : WorkspaceTestBase
     }
 
     [Fact]
-    public void ProjectState_WithHostProjectAndWorkspaceState_ResetsImportedDocuments()
+    public void ProjectState_WithHostProject_ResetsImportedDocuments()
     {
         // Arrange
         var original = ProjectState.Create(ProjectEngineFactoryProvider, LanguageServerFeatureOptions, _hostProject, _projectWorkspaceState);
         original = original.WithAddedHostDocument(TestProjectData.SomeProjectFile1, DocumentState.EmptyLoader);
 
         // Act
-        var state = original.WithHostProjectAndWorkspaceState(_hostProjectWithConfigurationChange, _projectWorkspaceState);
+        var state = original.WithHostProject(_hostProjectWithConfigurationChange);
 
         // Assert
         var importMap = Assert.Single(state.ImportsToRelatedDocuments);
@@ -643,7 +643,7 @@ public class ProjectStateTest : WorkspaceTestBase
     }
 
     [Fact]
-    public void ProjectState_WithHostProjectAndWorkspaceState_Changed()
+    public void ProjectState_WithProjectWorkspaceState_Changed()
     {
         // Arrange
         var original = ProjectState.Create(ProjectEngineFactoryProvider, LanguageServerFeatureOptions, _hostProject, _projectWorkspaceState)
@@ -657,7 +657,7 @@ public class ProjectStateTest : WorkspaceTestBase
         var changed = ProjectWorkspaceState.Create(_projectWorkspaceState.TagHelpers, LanguageVersion.CSharp6);
 
         // Act
-        var state = original.WithHostProjectAndWorkspaceState(_hostProject, changed);
+        var state = original.WithProjectWorkspaceState(changed);
 
         // Assert
         Assert.NotEqual(original.Version, state.Version);
@@ -682,7 +682,7 @@ public class ProjectStateTest : WorkspaceTestBase
     }
 
     [Fact]
-    public void ProjectState_WithHostProjectAndWorkspaceState_Changed_TagHelpersChanged()
+    public void ProjectState_WithProjectWorkspaceState_Changed_TagHelpersChanged()
     {
         // Arrange
         var original = ProjectState.Create(ProjectEngineFactoryProvider, LanguageServerFeatureOptions, _hostProject, _projectWorkspaceState)
@@ -696,7 +696,7 @@ public class ProjectStateTest : WorkspaceTestBase
         var changed = ProjectWorkspaceState.Default;
 
         // Act
-        var state = original.WithHostProjectAndWorkspaceState(_hostProject, changed);
+        var state = original.WithProjectWorkspaceState(changed);
 
         // Assert
         Assert.NotEqual(original.Version, state.Version);
@@ -716,7 +716,7 @@ public class ProjectStateTest : WorkspaceTestBase
     }
 
     [Fact]
-    public void ProjectState_WithHostProjectAndWorkspaceState_IdenticalState_Caches()
+    public void ProjectState_WithProjectWorkspaceState_IdenticalState_Caches()
     {
         // Arrange
         var original = ProjectState.Create(ProjectEngineFactoryProvider, LanguageServerFeatureOptions, _hostProject, _projectWorkspaceState)
@@ -730,21 +730,21 @@ public class ProjectStateTest : WorkspaceTestBase
         var changed = ProjectWorkspaceState.Create(original.TagHelpers, original.CSharpLanguageVersion);
 
         // Act
-        var state = original.WithHostProjectAndWorkspaceState(_hostProject, changed);
+        var state = original.WithProjectWorkspaceState(changed);
 
         // Assert
         Assert.Same(original, state);
     }
 
     [Fact]
-    public void ProjectState_WithHostProjectAndWorkspaceState_CallsWorkspaceProjectChangeOnDocumentState()
+    public void ProjectState_WithProjectWorkspaceState_CallsWorkspaceProjectChangeOnDocumentState()
     {
         // Arrange
         var callCount = 0;
 
         var documents = ImmutableDictionary.CreateBuilder<string, DocumentState>(FilePathComparer.Instance);
-        documents[_documents[1].FilePath] = TestDocumentState.Create(_documents[1], onConfigurationChange: () => callCount++);
-        documents[_documents[2].FilePath] = TestDocumentState.Create(_documents[2], onConfigurationChange: () => callCount++);
+        documents[_documents[1].FilePath] = TestDocumentState.Create(_documents[1], onProjectWorkspaceStateChange: () => callCount++);
+        documents[_documents[2].FilePath] = TestDocumentState.Create(_documents[2], onProjectWorkspaceStateChange: () => callCount++);
 
         var original = ProjectState.Create(ProjectEngineFactoryProvider, LanguageServerFeatureOptions, _hostProject, _projectWorkspaceState);
         original.Documents = documents.ToImmutable();
@@ -752,7 +752,7 @@ public class ProjectStateTest : WorkspaceTestBase
         var changed = ProjectWorkspaceState.Default;
 
         // Act
-        var state = original.WithHostProjectAndWorkspaceState(_hostProject, changed);
+        var state = original.WithProjectWorkspaceState(changed);
 
         // Assert
         Assert.NotEqual(original.Version, state.Version);
@@ -991,7 +991,8 @@ public class ProjectStateTest : WorkspaceTestBase
             Action? onTextChange = null,
             Action? onTextLoaderChange = null,
             Action? onConfigurationChange = null,
-            Action? onImportsChange = null)
+            Action? onImportsChange = null,
+            Action? onProjectWorkspaceStateChange = null)
         {
             return new TestDocumentState(
                 hostDocument,
@@ -999,13 +1000,15 @@ public class ProjectStateTest : WorkspaceTestBase
                 onTextChange,
                 onTextLoaderChange,
                 onConfigurationChange,
-                onImportsChange);
+                onImportsChange,
+                onProjectWorkspaceStateChange);
         }
 
         private readonly Action? _onTextChange;
         private readonly Action? _onTextLoaderChange;
         private readonly Action? _onConfigurationChange;
         private readonly Action? _onImportsChange;
+        private readonly Action? _onProjectWorkspaceStateChange;
 
         private TestDocumentState(
             HostDocument hostDocument,
@@ -1013,13 +1016,15 @@ public class ProjectStateTest : WorkspaceTestBase
             Action? onTextChange,
             Action? onTextLoaderChange,
             Action? onConfigurationChange,
-            Action? onImportsChange)
+            Action? onImportsChange,
+            Action? onProjectWorkspaceStateChange)
             : base(hostDocument, version: 1, loader ?? EmptyLoader)
         {
             _onTextChange = onTextChange;
             _onTextLoaderChange = onTextLoaderChange;
             _onConfigurationChange = onConfigurationChange;
             _onImportsChange = onImportsChange;
+            _onProjectWorkspaceStateChange = onProjectWorkspaceStateChange;
         }
 
         public override DocumentState WithText(SourceText sourceText, VersionStamp textVersion)
@@ -1034,10 +1039,10 @@ public class ProjectStateTest : WorkspaceTestBase
             return base.WithTextLoader(loader);
         }
 
-        public override DocumentState WithProjectChange()
+        public override DocumentState WithConfigurationChange()
         {
             _onConfigurationChange?.Invoke();
-            return base.WithProjectChange();
+            return base.WithConfigurationChange();
         }
 
         public override DocumentState WithImportsChange()
@@ -1045,5 +1050,11 @@ public class ProjectStateTest : WorkspaceTestBase
             _onImportsChange?.Invoke();
             return base.WithImportsChange();
         }
+
+        public override DocumentState WithProjectWorkspaceStateChange()
+        {
+            _onProjectWorkspaceStateChange?.Invoke();
+            return base.WithProjectWorkspaceStateChange();
+        }
     }
 }
diff --git a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/Tooltip/ProjectAvailabilityTests.cs b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/Tooltip/ProjectAvailabilityTests.cs
index 4abb011d44..d19a69bede 100644
--- a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/Tooltip/ProjectAvailabilityTests.cs
+++ b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/Tooltip/ProjectAvailabilityTests.cs
@@ -56,7 +56,7 @@ public class ProjectAvailabilityTests(ITestOutputHelper testOutput) : ToolingTes
         await projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(hostProject);
-            updater.ProjectChanged(hostProject, projectWorkspaceState);
+            updater.ProjectWorkspaceStateChanged(hostProject.Key, projectWorkspaceState);
             updater.DocumentAdded(hostProject.Key, hostDocument, TestMocks.CreateTextLoader(hostDocument.FilePath, text: ""));
         });
 
@@ -101,11 +101,11 @@ public class ProjectAvailabilityTests(ITestOutputHelper testOutput) : ToolingTes
         await projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(hostProject1);
-            updater.ProjectChanged(hostProject1, projectWorkspaceState);
+            updater.ProjectWorkspaceStateChanged(hostProject1.Key, projectWorkspaceState);
             updater.DocumentAdded(hostProject1.Key, hostDocument, TestMocks.CreateTextLoader(hostDocument.FilePath, text: ""));
 
             updater.ProjectAdded(hostProject2);
-            updater.ProjectChanged(hostProject2, projectWorkspaceState);
+            updater.ProjectWorkspaceStateChanged(hostProject2.Key, projectWorkspaceState);
             updater.DocumentAdded(hostProject2.Key, hostDocument, TestMocks.CreateTextLoader(hostDocument.FilePath, text: ""));
         });
 
@@ -150,7 +150,7 @@ public class ProjectAvailabilityTests(ITestOutputHelper testOutput) : ToolingTes
         await projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(hostProject1);
-            updater.ProjectChanged(hostProject1, projectWorkspaceState);
+            updater.ProjectWorkspaceStateChanged(hostProject1.Key, projectWorkspaceState);
             updater.DocumentAdded(hostProject1.Key, hostDocument, TestMocks.CreateTextLoader(hostDocument.FilePath, text: ""));
 
             updater.ProjectAdded(hostProject2);
diff --git a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/LiveShare/Guest/ProjectSnapshotSynchronizationServiceTest.cs b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/LiveShare/Guest/ProjectSnapshotSynchronizationServiceTest.cs
index 280e6a1295..729a6f2462 100644
--- a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/LiveShare/Guest/ProjectSnapshotSynchronizationServiceTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/LiveShare/Guest/ProjectSnapshotSynchronizationServiceTest.cs
@@ -170,7 +170,7 @@ public class ProjectSnapshotSynchronizationServiceTest : VisualStudioWorkspaceTe
         await _projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(hostProject);
-            updater.ProjectChanged(hostProject, newHandle.ProjectWorkspaceState);
+            updater.ProjectConfigurationChanged(hostProject);
         });
 
         var args = new ProjectChangeEventProxyArgs(oldHandle, newHandle, ProjectProxyChangeKind.ProjectChanged);
@@ -214,7 +214,7 @@ public class ProjectSnapshotSynchronizationServiceTest : VisualStudioWorkspaceTe
         await _projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(hostProject);
-            updater.ProjectChanged(hostProject, oldHandle.ProjectWorkspaceState);
+            updater.ProjectWorkspaceStateChanged(hostProject.Key, oldHandle.ProjectWorkspaceState);
         });
 
         var args = new ProjectChangeEventProxyArgs(oldHandle, newHandle, ProjectProxyChangeKind.ProjectChanged);
diff --git a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/LiveShare/Host/ProjectSnapshotManagerProxyTest.cs b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/LiveShare/Host/ProjectSnapshotManagerProxyTest.cs
index ff77fe3c30..12e9c3e829 100644
--- a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/LiveShare/Host/ProjectSnapshotManagerProxyTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/LiveShare/Host/ProjectSnapshotManagerProxyTest.cs
@@ -44,10 +44,10 @@ public class ProjectSnapshotManagerProxyTest(ITestOutputHelper testOutput) : Vis
         await projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(_hostProject1);
-            updater.ProjectChanged(_hostProject1, _projectWorkspaceState1);
+            updater.ProjectWorkspaceStateChanged(_hostProject1.Key, _projectWorkspaceState1);
 
             updater.ProjectAdded(_hostProject2);
-            updater.ProjectChanged(_hostProject2, _projectWorkspaceState2);
+            updater.ProjectWorkspaceStateChanged(_hostProject2.Key, _projectWorkspaceState2);
         });
 
         using var proxy = new ProjectSnapshotManagerProxy(
@@ -77,7 +77,7 @@ public class ProjectSnapshotManagerProxyTest(ITestOutputHelper testOutput) : Vis
         await projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(_hostProject1);
-            updater.ProjectChanged(_hostProject1, _projectWorkspaceState1);
+            updater.ProjectWorkspaceStateChanged(_hostProject1.Key, _projectWorkspaceState1);
         });
 
         using var proxy = new ProjectSnapshotManagerProxy(
@@ -102,13 +102,12 @@ public class ProjectSnapshotManagerProxyTest(ITestOutputHelper testOutput) : Vis
         {
             // Change the project's configuration to force a changed event to be raised.
             var project = updater.GetLoadedProject(_hostProject1.Key);
-            updater.ProjectChanged(new(
+            updater.ProjectConfigurationChanged(new(
                 project.FilePath,
                 project.IntermediateOutputPath,
                 FallbackRazorConfiguration.MVC_1_0,
                 project.RootNamespace,
-                project.DisplayName),
-                _projectWorkspaceState1);
+                project.DisplayName));
         });
 
         await proxyAccessor.ProcessingChangedEventTestTask.AssumeNotNull().JoinAsync();
@@ -126,7 +125,7 @@ public class ProjectSnapshotManagerProxyTest(ITestOutputHelper testOutput) : Vis
         await projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(_hostProject1);
-            updater.ProjectChanged(_hostProject1, _projectWorkspaceState1);
+            updater.ProjectWorkspaceStateChanged(_hostProject1.Key, _projectWorkspaceState1);
         });
 
         var proxy = new ProjectSnapshotManagerProxy(
@@ -144,13 +143,12 @@ public class ProjectSnapshotManagerProxyTest(ITestOutputHelper testOutput) : Vis
         {
             // Change the project's configuration to force a changed event to be raised.
             var project = updater.GetLoadedProject(_hostProject1.Key);
-            updater.ProjectChanged(new(
+            updater.ProjectConfigurationChanged(new(
                 project.FilePath,
                 project.IntermediateOutputPath,
                 FallbackRazorConfiguration.MVC_1_0,
                 project.RootNamespace,
-                project.DisplayName),
-                _projectWorkspaceState1);
+                project.DisplayName));
         });
 
         // Assert
@@ -166,7 +164,7 @@ public class ProjectSnapshotManagerProxyTest(ITestOutputHelper testOutput) : Vis
         await projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(_hostProject1);
-            updater.ProjectChanged(_hostProject1, _projectWorkspaceState1);
+            updater.ProjectWorkspaceStateChanged(_hostProject1.Key, _projectWorkspaceState1);
         });
 
         using var proxy = new ProjectSnapshotManagerProxy(
@@ -198,10 +196,10 @@ public class ProjectSnapshotManagerProxyTest(ITestOutputHelper testOutput) : Vis
         await projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(_hostProject1);
-            updater.ProjectChanged(_hostProject1, _projectWorkspaceState1);
+            updater.ProjectWorkspaceStateChanged(_hostProject1.Key, _projectWorkspaceState1);
 
             updater.ProjectAdded(_hostProject2);
-            updater.ProjectChanged(_hostProject2, _projectWorkspaceState2);
+            updater.ProjectWorkspaceStateChanged(_hostProject2.Key, _projectWorkspaceState2);
         });
 
         using var proxy = new ProjectSnapshotManagerProxy(
@@ -231,7 +229,7 @@ public class ProjectSnapshotManagerProxyTest(ITestOutputHelper testOutput) : Vis
         await projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(_hostProject1);
-            updater.ProjectChanged(_hostProject1, _projectWorkspaceState1);
+            updater.ProjectWorkspaceStateChanged(_hostProject1.Key, _projectWorkspaceState1);
         });
 
         using var proxy = new ProjectSnapshotManagerProxy(
diff --git a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectSystem/FallbackProjectManagerTest.cs b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectSystem/FallbackProjectManagerTest.cs
index 0e5511874e..57d07c5b99 100644
--- a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectSystem/FallbackProjectManagerTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectSystem/FallbackProjectManagerTest.cs
@@ -5,7 +5,6 @@ using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor.Language;
-using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Telemetry;
 using Microsoft.AspNetCore.Razor.Test.Common.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Test.Common.VisualStudio;
@@ -143,7 +142,7 @@ public class FallbackProjectManagerTest : VisualStudioWorkspaceTestBase
 
         await _projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(hostProject, ProjectWorkspaceState.Default);
+            updater.ProjectConfigurationChanged(hostProject);
         });
 
         project = Assert.Single(_projectManager.GetProjects());
diff --git a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectSystem/ProjectSnapshotManagerTest.cs b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectSystem/ProjectSnapshotManagerTest.cs
index 149e604c20..6f127b659d 100644
--- a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectSystem/ProjectSnapshotManagerTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectSystem/ProjectSnapshotManagerTest.cs
@@ -268,7 +268,7 @@ public class ProjectSnapshotManagerTest : VisualStudioWorkspaceTestBase
         await _projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(s_hostProject);
-            updater.ProjectChanged(s_hostProject, _projectWorkspaceStateWithTagHelpers);
+            updater.ProjectWorkspaceStateChanged(s_hostProject.Key, _projectWorkspaceStateWithTagHelpers);
         });
 
         var originalTagHelpers = await _projectManager.GetLoadedProject(s_hostProject.Key).GetTagHelpersAsync(DisposalToken);
@@ -390,7 +390,7 @@ public class ProjectSnapshotManagerTest : VisualStudioWorkspaceTestBase
         await _projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(s_hostProject);
-            updater.ProjectChanged(s_hostProject, _projectWorkspaceStateWithTagHelpers);
+            updater.ProjectWorkspaceStateChanged(s_hostProject.Key, _projectWorkspaceStateWithTagHelpers);
             updater.DocumentAdded(s_hostProject.Key, s_documents[0], s_documents[0].CreateEmptyTextLoader());
             updater.DocumentAdded(s_hostProject.Key, s_documents[1], s_documents[1].CreateEmptyTextLoader());
             updater.DocumentAdded(s_hostProject.Key, s_documents[2], s_documents[2].CreateEmptyTextLoader());
@@ -640,7 +640,7 @@ public class ProjectSnapshotManagerTest : VisualStudioWorkspaceTestBase
         // Act
         await _projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(s_hostProjectWithConfigurationChange, ProjectWorkspaceState.Default);
+            updater.ProjectConfigurationChanged(s_hostProjectWithConfigurationChange);
         });
 
         // Assert
@@ -655,7 +655,7 @@ public class ProjectSnapshotManagerTest : VisualStudioWorkspaceTestBase
         await _projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(s_hostProject);
-            updater.ProjectChanged(s_hostProject, _projectWorkspaceStateWithTagHelpers);
+            updater.ProjectWorkspaceStateChanged(s_hostProject.Key, _projectWorkspaceStateWithTagHelpers);
         });
 
         using var listener = _projectManager.ListenToNotifications();
@@ -663,7 +663,7 @@ public class ProjectSnapshotManagerTest : VisualStudioWorkspaceTestBase
         // Act
         await _projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(s_hostProjectWithConfigurationChange, _projectWorkspaceStateWithTagHelpers);
+            updater.ProjectConfigurationChanged(s_hostProjectWithConfigurationChange);
         });
 
         // Assert
@@ -686,7 +686,7 @@ public class ProjectSnapshotManagerTest : VisualStudioWorkspaceTestBase
         // Act
         await _projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(s_hostProjectWithConfigurationChange, ProjectWorkspaceState.Default);
+            updater.ProjectConfigurationChanged(s_hostProjectWithConfigurationChange);
         });
 
         // Assert
@@ -703,7 +703,7 @@ public class ProjectSnapshotManagerTest : VisualStudioWorkspaceTestBase
         // Act
         await _projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(s_hostProject, ProjectWorkspaceState.Default);
+            updater.ProjectConfigurationChanged(s_hostProject);
         });
 
         // Assert
@@ -745,7 +745,7 @@ public class ProjectSnapshotManagerTest : VisualStudioWorkspaceTestBase
         // Act
         await _projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(s_hostProject, _projectWorkspaceStateWithTagHelpers);
+            updater.ProjectWorkspaceStateChanged(s_hostProject.Key, _projectWorkspaceStateWithTagHelpers);
         });
 
         // Assert
@@ -767,7 +767,7 @@ public class ProjectSnapshotManagerTest : VisualStudioWorkspaceTestBase
         // Act
         await _projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(s_hostProject, _projectWorkspaceStateWithTagHelpers);
+            updater.ProjectWorkspaceStateChanged(s_hostProject.Key, _projectWorkspaceStateWithTagHelpers);
         });
 
         // Assert
@@ -791,7 +791,7 @@ public class ProjectSnapshotManagerTest : VisualStudioWorkspaceTestBase
         // Act
         await _projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(s_hostProject, _projectWorkspaceStateWithTagHelpers);
+            updater.ProjectWorkspaceStateChanged(s_hostProject.Key, _projectWorkspaceStateWithTagHelpers);
         });
 
         // Assert
@@ -806,7 +806,7 @@ public class ProjectSnapshotManagerTest : VisualStudioWorkspaceTestBase
         await _projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(s_hostProject);
-            updater.ProjectChanged(s_hostProject, ProjectWorkspaceState.Default);
+            updater.ProjectWorkspaceStateChanged(s_hostProject.Key, ProjectWorkspaceState.Default);
         });
 
         using var listener = _projectManager.ListenToNotifications();
@@ -814,7 +814,7 @@ public class ProjectSnapshotManagerTest : VisualStudioWorkspaceTestBase
         // Act
         await _projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(s_hostProject, _projectWorkspaceStateWithTagHelpers);
+            updater.ProjectWorkspaceStateChanged(s_hostProject.Key, _projectWorkspaceStateWithTagHelpers);
         });
 
         // Assert
diff --git a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectWorkspaceStateGeneratorTest.cs b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectWorkspaceStateGeneratorTest.cs
index 44973fea64..c1dca22323 100644
--- a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectWorkspaceStateGeneratorTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectWorkspaceStateGeneratorTest.cs
@@ -120,7 +120,7 @@ public class ProjectWorkspaceStateGeneratorTest : VisualStudioWorkspaceTestBase
         await _projectManager.UpdateAsync(updater =>
         {
             updater.ProjectAdded(_projectSnapshot.HostProject);
-            updater.ProjectChanged(_projectSnapshot.HostProject, _projectWorkspaceStateWithTagHelpers);
+            updater.ProjectWorkspaceStateChanged(_projectSnapshot.Key, _projectWorkspaceStateWithTagHelpers);
         });
 
         // Act
diff --git a/src/Razor/test/Microsoft.VisualStudio.LegacyEditor.Razor.Test/VisualStudioDocumentTrackerTest.cs b/src/Razor/test/Microsoft.VisualStudio.LegacyEditor.Razor.Test/VisualStudioDocumentTrackerTest.cs
index 2d2f16ba30..adf75ef0fa 100644
--- a/src/Razor/test/Microsoft.VisualStudio.LegacyEditor.Razor.Test/VisualStudioDocumentTrackerTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.LegacyEditor.Razor.Test/VisualStudioDocumentTrackerTest.cs
@@ -4,7 +4,6 @@
 using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Test.Common;
 using Microsoft.AspNetCore.Razor.Test.Common.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Test.Common.VisualStudio;
@@ -471,7 +470,7 @@ public class VisualStudioDocumentTrackerTest : VisualStudioWorkspaceTestBase
         // Act
         await _projectManager.UpdateAsync(updater =>
         {
-            updater.ProjectChanged(_updatedHostProject, ProjectWorkspaceState.Default);
+            updater.ProjectConfigurationChanged(_updatedHostProject);
         });
 
         // Assert