diff --git a/dom/script/ModuleLoadRequest.cpp b/dom/script/ModuleLoadRequest.cpp
index 3da68bf6bd0c..ae394456648f 100644
--- a/dom/script/ModuleLoadRequest.cpp
+++ b/dom/script/ModuleLoadRequest.cpp
@@ -5,6 +5,9 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "ModuleLoadRequest.h"
+
+#include "mozilla/HoldDropJSObjects.h"
+
 #include "ModuleScript.h"
 #include "ScriptLoader.h"
 
@@ -18,35 +21,92 @@ namespace dom {
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ModuleLoadRequest)
 NS_INTERFACE_MAP_END_INHERITING(ScriptLoadRequest)
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(ModuleLoadRequest, ScriptLoadRequest,
-                                   mBaseURL, mLoader, mModuleScript, mImports)
+NS_IMPL_CYCLE_COLLECTION_CLASS(ModuleLoadRequest)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(ModuleLoadRequest,
+                                                ScriptLoadRequest)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mBaseURL, mLoader, mModuleScript, mImports)
+  tmp->ClearDynamicImport();
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(ModuleLoadRequest,
+                                                  ScriptLoadRequest)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mBaseURL, mLoader, mModuleScript, mImports)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(ModuleLoadRequest,
+                                               ScriptLoadRequest)
+  NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mDynamicReferencingPrivate)
+  NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mDynamicSpecifier)
+  NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mDynamicPromise)
+NS_IMPL_CYCLE_COLLECTION_TRACE_END
 
 NS_IMPL_ADDREF_INHERITED(ModuleLoadRequest, ScriptLoadRequest)
 NS_IMPL_RELEASE_INHERITED(ModuleLoadRequest, ScriptLoadRequest)
 
-ModuleLoadRequest::ModuleLoadRequest(nsIURI* aURI,
-                                     ScriptFetchOptions* aFetchOptions,
-                                     const SRIMetadata& aIntegrity,
-                                     nsIURI* aReferrer, ScriptLoader* aLoader)
+static VisitedURLSet* NewVisitedSetForTopLevelImport(nsIURI* aURI) {
+  auto set = new VisitedURLSet();
+  set->PutEntry(aURI);
+  return set;
+}
+
+/* static */ ModuleLoadRequest* ModuleLoadRequest::CreateTopLevel(
+    nsIURI* aURI, ScriptFetchOptions* aFetchOptions,
+    const SRIMetadata& aIntegrity, nsIURI* aReferrer, ScriptLoader* aLoader) {
+  return new ModuleLoadRequest(aURI, aFetchOptions, aIntegrity, aReferrer,
+                               true,  /* is top level */
+                               false, /* is dynamic import */
+                               aLoader, NewVisitedSetForTopLevelImport(aURI));
+}
+
+/* static */ ModuleLoadRequest* ModuleLoadRequest::CreateStaticImport(
+    nsIURI* aURI, ModuleLoadRequest* aParent) {
+  auto request =
+      new ModuleLoadRequest(aURI, aParent->mFetchOptions, SRIMetadata(),
+                            aParent->mURI, false, /* is top level */
+                            false,                /* is dynamic import */
+                            aParent->mLoader, aParent->mVisitedSet);
+
+  request->mIsInline = false;
+  request->mScriptMode = aParent->mScriptMode;
+
+  return request;
+}
+
+/* static */ ModuleLoadRequest* ModuleLoadRequest::CreateDynamicImport(
+    nsIURI* aURI, ModuleScript* aScript,
+    JS::Handle<JS::Value> aReferencingPrivate, JS::Handle<JSString*> aSpecifier,
+    JS::Handle<JSObject*> aPromise) {
+  MOZ_ASSERT(aSpecifier);
+  MOZ_ASSERT(aPromise);
+
+  auto request = new ModuleLoadRequest(
+      aURI, aScript->FetchOptions(), SRIMetadata(), aScript->BaseURL(),
+      true, /* is top level */
+      true, /* is dynamic import */
+      aScript->Loader(), NewVisitedSetForTopLevelImport(aURI));
+
+  request->mIsInline = false;
+  request->mScriptMode = ScriptMode::eAsync;
+  request->mDynamicReferencingPrivate = aReferencingPrivate;
+  request->mDynamicSpecifier = aSpecifier;
+  request->mDynamicPromise = aPromise;
+
+  HoldJSObjects(request);
+
+  return request;
+}
+
+ModuleLoadRequest::ModuleLoadRequest(
+    nsIURI* aURI, ScriptFetchOptions* aFetchOptions,
+    const SRIMetadata& aIntegrity, nsIURI* aReferrer, bool aIsTopLevel,
+    bool aIsDynamicImport, ScriptLoader* aLoader, VisitedURLSet* aVisitedSet)
     : ScriptLoadRequest(ScriptKind::eModule, aURI, aFetchOptions, aIntegrity,
                         aReferrer),
-      mIsTopLevel(true),
+      mIsTopLevel(aIsTopLevel),
+      mIsDynamicImport(aIsDynamicImport),
       mLoader(aLoader),
-      mVisitedSet(new VisitedURLSet()) {
-  mVisitedSet->PutEntry(aURI);
-}
-
-ModuleLoadRequest::ModuleLoadRequest(nsIURI* aURI, ModuleLoadRequest* aParent)
-    : ScriptLoadRequest(ScriptKind::eModule, aURI, aParent->mFetchOptions,
-                        SRIMetadata(), aParent->mURI),
-      mIsTopLevel(false),
-      mLoader(aParent->mLoader),
-      mVisitedSet(aParent->mVisitedSet) {
-  MOZ_ASSERT(mVisitedSet->Contains(aURI));
-
-  mIsInline = false;
-  mScriptMode = aParent->mScriptMode;
-}
+      mVisitedSet(aVisitedSet) {}
 
 void ModuleLoadRequest::Cancel() {
   ScriptLoadRequest::Cancel();
@@ -138,5 +198,11 @@ void ModuleLoadRequest::LoadFinished() {
   mLoader = nullptr;
 }
 
+void ModuleLoadRequest::ClearDynamicImport() {
+  mDynamicReferencingPrivate = JS::UndefinedValue();
+  mDynamicSpecifier = nullptr;
+  mDynamicPromise = nullptr;
+}
+
 }  // namespace dom
 }  // namespace mozilla
diff --git a/dom/script/ModuleLoadRequest.h b/dom/script/ModuleLoadRequest.h
index 4d98d3e3fab9..b45a95d3795c 100644
--- a/dom/script/ModuleLoadRequest.h
+++ b/dom/script/ModuleLoadRequest.h
@@ -36,22 +36,40 @@ class ModuleLoadRequest final : public ScriptLoadRequest {
   ModuleLoadRequest(const ModuleLoadRequest& aOther) = delete;
   ModuleLoadRequest(ModuleLoadRequest&& aOther) = delete;
 
- public:
-  NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ModuleLoadRequest, ScriptLoadRequest)
-
-  // Create a top-level module load request.
   ModuleLoadRequest(nsIURI* aURI, ScriptFetchOptions* aFetchOptions,
                     const SRIMetadata& aIntegrity, nsIURI* aReferrer,
-                    ScriptLoader* aLoader);
+                    bool aIsTopLevel, bool aIsDynamicImport,
+                    ScriptLoader* aLoader, VisitedURLSet* aVisitedSet);
 
-  // Create a module load request for an imported module.
-  ModuleLoadRequest(nsIURI* aURI, ModuleLoadRequest* aParent);
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(ModuleLoadRequest,
+                                                         ScriptLoadRequest)
+
+  // Create a top-level module load request.
+  static ModuleLoadRequest* CreateTopLevel(nsIURI* aURI,
+                                           ScriptFetchOptions* aFetchOptions,
+                                           const SRIMetadata& aIntegrity,
+                                           nsIURI* aReferrer,
+                                           ScriptLoader* aLoader);
+
+  // Create a module load request for a static module import.
+  static ModuleLoadRequest* CreateStaticImport(nsIURI* aURI,
+                                               ModuleLoadRequest* aParent);
+
+  // Create a module load request for dynamic module import.
+  static ModuleLoadRequest* CreateDynamicImport(
+      nsIURI* aURI, ModuleScript* aScript,
+      JS::Handle<JS::Value> aReferencingPrivate,
+      JS::Handle<JSString*> aSpecifier, JS::Handle<JSObject*> aPromise);
 
   bool IsTopLevel() const override { return mIsTopLevel; }
 
+  bool IsDynamicImport() const { return mIsDynamicImport; }
+
   void SetReady() override;
   void Cancel() override;
+  void ClearDynamicImport();
 
   void ModuleLoaded();
   void ModuleErrored();
@@ -66,6 +84,9 @@ class ModuleLoadRequest final : public ScriptLoadRequest {
   // Is this a request for a top level module script or an import?
   const bool mIsTopLevel;
 
+  // Is this the top level request for a dynamic module import?
+  const bool mIsDynamicImport;
+
   // The base URL used for resolving relative module imports.
   nsCOMPtr<nsIURI> mBaseURL;
 
@@ -88,6 +109,11 @@ class ModuleLoadRequest final : public ScriptLoadRequest {
   // Set of module URLs visited while fetching the module graph this request is
   // part of.
   RefPtr<VisitedURLSet> mVisitedSet;
+
+  // For dynamic imports, the details to pass to FinishDynamicImport.
+  JS::Heap<JS::Value> mDynamicReferencingPrivate;
+  JS::Heap<JSString*> mDynamicSpecifier;
+  JS::Heap<JSObject*> mDynamicPromise;
 };
 
 }  // namespace dom
diff --git a/dom/script/ModuleScript.cpp b/dom/script/ModuleScript.cpp
index 708c78753376..04e7ebaa0751 100644
--- a/dom/script/ModuleScript.cpp
+++ b/dom/script/ModuleScript.cpp
@@ -5,7 +5,10 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "ModuleScript.h"
+
 #include "mozilla/HoldDropJSObjects.h"
+
+#include "jsfriendapi.h"
 #include "ScriptLoader.h"
 
 namespace mozilla {
@@ -20,6 +23,7 @@ NS_IMPL_CYCLE_COLLECTION_CLASS(ModuleScript)
 
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(ModuleScript)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mLoader)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mFetchOptions)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mBaseURL)
   tmp->UnlinkModuleRecord();
   tmp->mParseError.setUndefined();
@@ -28,6 +32,7 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(ModuleScript)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mLoader)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mFetchOptions)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(ModuleScript)
@@ -39,9 +44,14 @@ NS_IMPL_CYCLE_COLLECTION_TRACE_END
 NS_IMPL_CYCLE_COLLECTING_ADDREF(ModuleScript)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(ModuleScript)
 
-ModuleScript::ModuleScript(ScriptLoader* aLoader, nsIURI* aBaseURL)
-    : mLoader(aLoader), mBaseURL(aBaseURL), mSourceElementAssociated(false) {
+ModuleScript::ModuleScript(ScriptLoader* aLoader,
+                           ScriptFetchOptions* aFetchOptions, nsIURI* aBaseURL)
+    : mLoader(aLoader),
+      mFetchOptions(aFetchOptions),
+      mBaseURL(aBaseURL),
+      mSourceElementAssociated(false) {
   MOZ_ASSERT(mLoader);
+  MOZ_ASSERT(mFetchOptions);
   MOZ_ASSERT(mBaseURL);
   MOZ_ASSERT(!mModuleRecord);
   MOZ_ASSERT(!HasParseError());
@@ -49,11 +59,14 @@ ModuleScript::ModuleScript(ScriptLoader* aLoader, nsIURI* aBaseURL)
 }
 
 void ModuleScript::UnlinkModuleRecord() {
-  // Remove module's back reference to this object request if present.
+  // Remove the module record's pointer to this object if present and
+  // decrement our reference count. The reference is added by
+  // SetModuleRecord() below.
   if (mModuleRecord) {
     MOZ_ASSERT(JS::GetModulePrivate(mModuleRecord).toPrivate() == this);
     JS::SetModulePrivate(mModuleRecord, JS::UndefinedValue());
     mModuleRecord = nullptr;
+    Release();
   }
 }
 
@@ -70,10 +83,21 @@ void ModuleScript::SetModuleRecord(JS::Handle<JSObject*> aModuleRecord) {
 
   mModuleRecord = aModuleRecord;
 
-  // Make module's host defined field point to this module script object.
-  // This is cleared in the UnlinkModuleRecord().
+  // Make module's host defined field point to this object and
+  // increment our reference count. This is decremented by
+  // UnlinkModuleRecord() above.
   JS::SetModulePrivate(mModuleRecord, JS::PrivateValue(this));
   HoldJSObjects(this);
+  AddRef();
+}
+
+void HostFinalizeTopLevelScript(JSFreeOp* aFop, const JS::Value& aPrivate) {
+  auto script = static_cast<ModuleScript*>(aPrivate.toPrivate());
+  if (script) {
+    MOZ_ASSERT(JS::GetModulePrivate(script->mModuleRecord.unbarrieredGet()) ==
+               aPrivate);
+    script->UnlinkModuleRecord();
+  }
 }
 
 void ModuleScript::SetParseError(const JS::Value& aError) {
@@ -88,7 +112,6 @@ void ModuleScript::SetParseError(const JS::Value& aError) {
 
 void ModuleScript::SetErrorToRethrow(const JS::Value& aError) {
   MOZ_ASSERT(!aError.isUndefined());
-  MOZ_ASSERT(!HasErrorToRethrow());
 
   // This is only called after SetModuleRecord() or SetParseError() so we don't
   // need to call HoldJSObjects() here.
diff --git a/dom/script/ModuleScript.h b/dom/script/ModuleScript.h
index 8aa842282f3c..48f8eb35e3a5 100644
--- a/dom/script/ModuleScript.h
+++ b/dom/script/ModuleScript.h
@@ -18,8 +18,11 @@ namespace dom {
 
 class ScriptLoader;
 
+void HostFinalizeTopLevelScript(JSFreeOp* aFop, const JS::Value& aPrivate);
+
 class ModuleScript final : public nsISupports {
   RefPtr<ScriptLoader> mLoader;
+  RefPtr<ScriptFetchOptions> mFetchOptions;
   nsCOMPtr<nsIURI> mBaseURL;
   JS::Heap<JSObject*> mModuleRecord;
   JS::Heap<JS::Value> mParseError;
@@ -32,7 +35,8 @@ class ModuleScript final : public nsISupports {
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(ModuleScript)
 
-  ModuleScript(ScriptLoader* aLoader, nsIURI* aBaseURL);
+  ModuleScript(ScriptLoader* aLoader, ScriptFetchOptions* aFetchOptions,
+               nsIURI* aBaseURL);
 
   void SetModuleRecord(JS::Handle<JSObject*> aModuleRecord);
   void SetParseError(const JS::Value& aError);
@@ -40,6 +44,7 @@ class ModuleScript final : public nsISupports {
   void SetSourceElementAssociated();
 
   ScriptLoader* Loader() const { return mLoader; }
+  ScriptFetchOptions* FetchOptions() const { return mFetchOptions; }
   JSObject* ModuleRecord() const { return mModuleRecord; }
   nsIURI* BaseURL() const { return mBaseURL; }
   JS::Value ParseError() const { return mParseError; }
@@ -49,6 +54,8 @@ class ModuleScript final : public nsISupports {
   bool SourceElementAssociated() const { return mSourceElementAssociated; }
 
   void UnlinkModuleRecord();
+
+  friend void HostFinalizeTopLevelScript(JSFreeOp*, const JS::Value&);
 };
 
 }  // namespace dom
diff --git a/dom/script/ScriptLoadRequest.cpp b/dom/script/ScriptLoadRequest.cpp
index cf4bb0030a0e..ff4c6538287d 100644
--- a/dom/script/ScriptLoadRequest.cpp
+++ b/dom/script/ScriptLoadRequest.cpp
@@ -4,7 +4,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#include "ModuleLoadRequest.h"
+#include "ScriptLoadRequest.h"
 
 #include "mozilla/HoldDropJSObjects.h"
 #include "mozilla/Unused.h"
@@ -52,6 +52,7 @@ NS_IMPL_CYCLE_COLLECTION_CLASS(ScriptLoadRequest)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(ScriptLoadRequest)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mFetchOptions)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mCacheInfo)
+  tmp->mScript = nullptr;
   tmp->DropBytecodeCacheReferences();
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
@@ -105,6 +106,8 @@ ScriptLoadRequest::~ScriptLoadRequest() {
   if (mScript) {
     DropBytecodeCacheReferences();
   }
+
+  DropJSObjects(this);
 }
 
 void ScriptLoadRequest::SetReady() {
@@ -207,6 +210,12 @@ void ScriptLoadRequest::ClearScriptSource() {
   }
 }
 
+void ScriptLoadRequest::SetScript(JSScript* aScript) {
+  MOZ_ASSERT(!mScript);
+  mScript = aScript;
+  HoldJSObjects(this);
+}
+
 //////////////////////////////////////////////////////////////
 // ScriptLoadRequestList
 //////////////////////////////////////////////////////////////
diff --git a/dom/script/ScriptLoadRequest.h b/dom/script/ScriptLoadRequest.h
index 2580eab11178..20672e77bd61 100644
--- a/dom/script/ScriptLoadRequest.h
+++ b/dom/script/ScriptLoadRequest.h
@@ -210,6 +210,8 @@ class ScriptLoadRequest
 
   void ClearScriptSource();
 
+  void SetScript(JSScript* aScript);
+
   void MaybeCancelOffThreadScript();
   void DropBytecodeCacheReferences();
 
diff --git a/dom/script/ScriptLoader.cpp b/dom/script/ScriptLoader.cpp
index 701e09f2d736..7edd5742eb03 100644
--- a/dom/script/ScriptLoader.cpp
+++ b/dom/script/ScriptLoader.cpp
@@ -113,9 +113,9 @@ NS_INTERFACE_MAP_END
 
 NS_IMPL_CYCLE_COLLECTION(ScriptLoader, mNonAsyncExternalScriptInsertedRequests,
                          mLoadingAsyncRequests, mLoadedAsyncRequests,
-                         mDeferRequests, mXSLTRequests, mParserBlockingRequest,
-                         mBytecodeEncodingQueue, mPreloads,
-                         mPendingChildLoaders, mFetchedModules)
+                         mDeferRequests, mXSLTRequests, mDynamicImportRequests,
+                         mParserBlockingRequest, mBytecodeEncodingQueue,
+                         mPreloads, mPendingChildLoaders, mFetchedModules)
 
 NS_IMPL_CYCLE_COLLECTING_ADDREF(ScriptLoader)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(ScriptLoader)
@@ -133,6 +133,7 @@ ScriptLoader::ScriptLoader(nsIDocument* aDocument)
       mGiveUpEncoding(false),
       mReporter(new ConsoleReportCollector()) {
   LOG(("ScriptLoader::ScriptLoader %p", this));
+  EnsureModuleHooksInitialized();
 }
 
 ScriptLoader::~ScriptLoader() {
@@ -164,6 +165,11 @@ ScriptLoader::~ScriptLoader() {
     req->FireScriptAvailable(NS_ERROR_ABORT);
   }
 
+  for (ScriptLoadRequest* req = mDynamicImportRequests.getFirst(); req;
+       req = req->getNext()) {
+    FinishDynamicImport(req->AsModuleRequest(), NS_ERROR_ABORT);
+  }
+
   for (ScriptLoadRequest* req =
            mNonAsyncExternalScriptInsertedRequests.getFirst();
        req; req = req->getNext()) {
@@ -471,7 +477,7 @@ nsresult ScriptLoader::CreateModuleScript(ModuleLoadRequest* aRequest) {
     MOZ_ASSERT(NS_SUCCEEDED(rv) == (module != nullptr));
 
     RefPtr<ModuleScript> moduleScript =
-        new ModuleScript(this, aRequest->mBaseURL);
+        new ModuleScript(this, aRequest->mFetchOptions, aRequest->mBaseURL);
     aRequest->mModuleScript = moduleScript;
 
     if (!module) {
@@ -689,7 +695,8 @@ RefPtr<GenericPromise> ScriptLoader::StartFetchingModuleAndDependencies(
     ModuleLoadRequest* aParent, nsIURI* aURI) {
   MOZ_ASSERT(aURI);
 
-  RefPtr<ModuleLoadRequest> childRequest = new ModuleLoadRequest(aURI, aParent);
+  RefPtr<ModuleLoadRequest> childRequest =
+      ModuleLoadRequest::CreateStaticImport(aURI, aParent);
 
   aParent->mImports.AppendElement(childRequest);
 
@@ -725,6 +732,12 @@ JSObject* HostResolveImportedModule(JSContext* aCx,
                                     JS::Handle<JS::Value> aReferencingPrivate,
                                     JS::Handle<JSString*> aSpecifier) {
   // Let referencing module script be referencingModule.[[HostDefined]].
+  if (aReferencingPrivate.isUndefined()) {
+    JS_ReportErrorNumberUC(aCx, js::GetErrorMessage, nullptr,
+                           JSMSG_IMPORT_SCRIPT_NOT_FOUND);
+    return nullptr;
+  }
+
   auto script = static_cast<ModuleScript*>(aReferencingPrivate.toPrivate());
   MOZ_ASSERT(JS::GetModulePrivate(script->ModuleRecord()) ==
              aReferencingPrivate);
@@ -774,14 +787,114 @@ bool HostPopulateImportMeta(JSContext* aCx,
                            JSPROP_ENUMERATE);
 }
 
-static void EnsureModuleResolveHook(JSContext* aCx) {
-  JSRuntime* rt = JS_GetRuntime(aCx);
+bool HostImportModuleDynamically(JSContext* aCx,
+                                 JS::Handle<JS::Value> aReferencingPrivate,
+                                 JS::Handle<JSString*> aSpecifier,
+                                 JS::Handle<JSObject*> aPromise) {
+  if (aReferencingPrivate.isUndefined()) {
+    JS_ReportErrorNumberUC(aCx, js::GetErrorMessage, nullptr,
+                           JSMSG_IMPORT_SCRIPT_NOT_FOUND);
+    return false;
+  }
+
+  auto script = static_cast<ModuleScript*>(aReferencingPrivate.toPrivate());
+  MOZ_ASSERT(JS::GetModulePrivate(script->ModuleRecord()) ==
+             aReferencingPrivate);
+
+  // Attempt to resolve the module specifier.
+  nsAutoJSString string;
+  if (!string.init(aCx, aSpecifier)) {
+    return false;
+  }
+
+  nsCOMPtr<nsIURI> uri = ResolveModuleSpecifier(script, string);
+  if (!uri) {
+    JS_ReportErrorNumberUC(aCx, js::GetErrorMessage, nullptr,
+                           JSMSG_BAD_MODULE_SPECIFIER, string.get());
+    return false;
+  }
+
+  // Create a new top-level load request.
+  RefPtr<ModuleLoadRequest> request = ModuleLoadRequest::CreateDynamicImport(
+      uri, script, aReferencingPrivate, aSpecifier, aPromise);
+
+  script->Loader()->StartDynamicImport(request);
+  return true;
+}
+
+void ScriptLoader::StartDynamicImport(ModuleLoadRequest* aRequest) {
+  LOG(("ScriptLoadRequest (%p): Start dynamic import", aRequest));
+
+  mDynamicImportRequests.AppendElement(aRequest);
+
+  nsresult rv = StartLoad(aRequest);
+  if (NS_FAILED(rv)) {
+    FinishDynamicImport(aRequest, rv);
+  }
+}
+
+void ScriptLoader::FinishDynamicImport(ModuleLoadRequest* aRequest,
+                                       nsresult aResult) {
+  AutoJSAPI jsapi;
+  MOZ_ALWAYS_TRUE(jsapi.Init(aRequest->mDynamicPromise));
+  FinishDynamicImport(jsapi.cx(), aRequest, aResult);
+}
+
+void ScriptLoader::FinishDynamicImport(JSContext* aCx,
+                                       ModuleLoadRequest* aRequest,
+                                       nsresult aResult) {
+  LOG(("ScriptLoadRequest (%p): Finish dynamic import %d %d", aRequest,
+       unsigned(aResult), JS_IsExceptionPending(aCx)));
+
+  // Complete the dynamic import, report failures indicated by aResult or as a
+  // pending exception on the context.
+
+  if (NS_FAILED(aResult)) {
+    MOZ_ASSERT(!JS_IsExceptionPending(aCx));
+    JS_ReportErrorNumberUC(aCx, js::GetErrorMessage, nullptr,
+                           JSMSG_IMPORT_SCRIPT_NOT_FOUND);
+  }
+
+  JS::Rooted<JS::Value> referencingScript(aCx,
+                                          aRequest->mDynamicReferencingPrivate);
+  JS::Rooted<JSString*> specifier(aCx, aRequest->mDynamicSpecifier);
+  JS::Rooted<JSObject*> promise(aCx, aRequest->mDynamicPromise);
+
+  JS::FinishDynamicModuleImport(aCx, referencingScript, specifier, promise);
+
+  // FinishDynamicModuleImport clears any pending exception.
+  MOZ_ASSERT(!JS_IsExceptionPending(aCx));
+
+  aRequest->ClearDynamicImport();
+}
+
+static void DynamicImportPrefChangedCallback(const char* aPrefName,
+                                             void* aClosure) {
+  bool enabled = Preferences::GetBool(aPrefName);
+  JS::ModuleDynamicImportHook hook =
+      enabled ? HostImportModuleDynamically : nullptr;
+
+  AutoJSAPI jsapi;
+  jsapi.Init();
+  JSRuntime* rt = JS_GetRuntime(jsapi.cx());
+  JS::SetModuleDynamicImportHook(rt, hook);
+}
+
+void ScriptLoader::EnsureModuleHooksInitialized() {
+  AutoJSAPI jsapi;
+  jsapi.Init();
+  JSRuntime* rt = JS_GetRuntime(jsapi.cx());
   if (JS::GetModuleResolveHook(rt)) {
     return;
   }
 
   JS::SetModuleResolveHook(rt, HostResolveImportedModule);
   JS::SetModuleMetadataHook(rt, HostPopulateImportMeta);
+  JS::SetScriptPrivateFinalizeHook(rt, HostFinalizeTopLevelScript);
+
+  Preferences::RegisterCallbackAndCall(DynamicImportPrefChangedCallback,
+                                       "javascript.options.dynamicImport",
+                                       (void*)nullptr);
 }
 
 void ScriptLoader::CheckModuleDependenciesLoaded(ModuleLoadRequest* aRequest) {
@@ -815,18 +928,34 @@ class ScriptRequestProcessor : public Runnable {
       : Runnable("dom::ScriptRequestProcessor"),
         mLoader(aLoader),
         mRequest(aRequest) {}
-  NS_IMETHOD Run() override { return mLoader->ProcessRequest(mRequest); }
+  NS_IMETHOD Run() override {
+    if (mRequest->IsModuleRequest() &&
+        mRequest->AsModuleRequest()->IsDynamicImport()) {
+      mLoader->ProcessDynamicImport(mRequest->AsModuleRequest());
+      return NS_OK;
+    }
+
+    return mLoader->ProcessRequest(mRequest);
+  }
 };
 
+void ScriptLoader::RunScriptWhenSafe(ScriptLoadRequest* aRequest) {
+  auto runnable = new ScriptRequestProcessor(this, aRequest);
+  nsContentUtils::AddScriptRunner(runnable);
+}
+
 void ScriptLoader::ProcessLoadedModuleTree(ModuleLoadRequest* aRequest) {
   MOZ_ASSERT(aRequest->IsReadyToRun());
 
   if (aRequest->IsTopLevel()) {
-    if (aRequest->mIsInline &&
-        aRequest->Element()->GetParserCreated() == NOT_FROM_PARSER) {
+    if (aRequest->IsDynamicImport()) {
+      MOZ_ASSERT(aRequest->isInList());
+      RefPtr<ScriptLoadRequest> req = mDynamicImportRequests.Steal(aRequest);
+      RunScriptWhenSafe(req);
+    } else if (aRequest->mIsInline &&
+               aRequest->Element()->GetParserCreated() == NOT_FROM_PARSER) {
       MOZ_ASSERT(!aRequest->isInList());
-      nsContentUtils::AddScriptRunner(
-          new ScriptRequestProcessor(this, aRequest));
+      RunScriptWhenSafe(aRequest);
     } else {
       MaybeMoveToLoadedList(aRequest);
       ProcessPendingRequests();
@@ -884,8 +1013,6 @@ bool ScriptLoader::InstantiateModuleTree(ModuleLoadRequest* aRequest) {
     return false;
   }
 
-  EnsureModuleResolveHook(jsapi.cx());
-
   JS::Rooted<JSObject*> module(jsapi.cx(), moduleScript->ModuleRecord());
   bool ok = NS_SUCCEEDED(nsJSUtils::ModuleInstantiate(jsapi.cx(), module));
 
@@ -1210,7 +1337,8 @@ ScriptLoadRequest* ScriptLoader::CreateLoadRequest(
   }
 
   MOZ_ASSERT(aKind == ScriptKind::eModule);
-  return new ModuleLoadRequest(aURI, fetchOptions, aIntegrity, referrer, this);
+  return ModuleLoadRequest::CreateTopLevel(aURI, fetchOptions, aIntegrity,
+                                           referrer, this);
 }
 
 bool ScriptLoader::ProcessScriptElement(nsIScriptElement* aElement) {
@@ -1538,7 +1666,7 @@ bool ScriptLoader::ProcessInlineScript(nsIScriptElement* aElement,
     NS_ASSERTION(
         !nsContentUtils::IsSafeToRunScript(),
         "A script-inserted script is inserted without an update batch?");
-    nsContentUtils::AddScriptRunner(new ScriptRequestProcessor(this, request));
+    RunScriptWhenSafe(request);
     return false;
   }
   if (aElement->GetParserCreated() == FROM_PARSER_NETWORK &&
@@ -1915,8 +2043,7 @@ nsresult ScriptLoader::ProcessRequest(ScriptLoadRequest* aRequest) {
 
   if (aRequest->IsModuleRequest()) {
     ModuleLoadRequest* request = aRequest->AsModuleRequest();
-    if (request->mModuleScript &&
-        !request->mModuleScript->HasErrorToRethrow()) {
+    if (request->mModuleScript) {
       if (!InstantiateModuleTree(request)) {
         request->mModuleScript = nullptr;
       }
@@ -2018,6 +2145,25 @@ nsresult ScriptLoader::ProcessRequest(ScriptLoadRequest* aRequest) {
   return rv;
 }
 
+void ScriptLoader::ProcessDynamicImport(ModuleLoadRequest* aRequest) {
+  if (aRequest->mModuleScript) {
+    if (!InstantiateModuleTree(aRequest)) {
+      aRequest->mModuleScript = nullptr;
+    }
+  }
+
+  nsresult rv = NS_ERROR_FAILURE;
+  if (aRequest->mModuleScript) {
+    rv = EvaluateScript(aRequest);
+  }
+
+  if (NS_FAILED(rv)) {
+    FinishDynamicImport(aRequest, rv);
+  }
+
+  return;
+}
+
 void ScriptLoader::FireScriptAvailable(nsresult aResult,
                                        ScriptLoadRequest* aRequest) {
   for (int32_t i = 0; i < mObservers.Count(); i++) {
@@ -2062,7 +2208,7 @@ already_AddRefed<nsIScriptGlobalObject> ScriptLoader::GetScriptGlobalObject() {
 }
 
 nsresult ScriptLoader::FillCompileOptionsForRequest(
-    const AutoJSAPI& jsapi, ScriptLoadRequest* aRequest,
+    const mozilla::dom::AutoJSAPI& jsapi, ScriptLoadRequest* aRequest,
     JS::Handle<JSObject*> aScopeChain, JS::CompileOptions* aOptions) {
   // It's very important to use aRequest->mURI, not the final URI of the channel
   // aRequest ended up getting script data from, as the script filename.
@@ -2203,6 +2349,19 @@ nsresult ScriptLoader::FillCompileOptionsForRequest(
   return true;
 }
 
+class MOZ_RAII AutoSetProcessingScriptTag {
+  nsCOMPtr<nsIScriptContext> mContext;
+  bool mOldTag;
+
+ public:
+  explicit AutoSetProcessingScriptTag(nsIScriptContext* aContext)
+      : mContext(aContext), mOldTag(mContext->GetProcessingScriptTag()) {
+    mContext->SetProcessingScriptTag(true);
+  }
+
+  ~AutoSetProcessingScriptTag() { mContext->SetProcessingScriptTag(mOldTag); }
+};
+
 nsresult ScriptLoader::EvaluateScript(ScriptLoadRequest* aRequest) {
   using namespace mozilla::Telemetry;
   MOZ_ASSERT(aRequest->IsReadyToRun());
@@ -2242,8 +2401,8 @@ nsresult ScriptLoader::EvaluateScript(ScriptLoadRequest* aRequest) {
   JSContext* cx = aes.cx();
   JS::Rooted<JSObject*> global(cx, globalObject->GetGlobalJSObject());
 
-  bool oldProcessingScriptTag = context->GetProcessingScriptTag();
-  context->SetProcessingScriptTag(true);
+  AutoSetProcessingScriptTag setProcessingScriptTag(context);
+
   nsresult rv;
   {
     if (aRequest->IsModuleRequest()) {
@@ -2255,8 +2414,6 @@ nsresult ScriptLoader::EvaluateScript(ScriptLoadRequest* aRequest) {
       // currentScript is set to null for modules.
       AutoCurrentScriptUpdater scriptUpdater(this, nullptr);
 
-      EnsureModuleResolveHook(cx);
-
       ModuleLoadRequest* request = aRequest->AsModuleRequest();
       MOZ_ASSERT(request->mModuleScript);
       MOZ_ASSERT(!request->mOffThreadToken);
@@ -2267,7 +2424,13 @@ nsresult ScriptLoader::EvaluateScript(ScriptLoadRequest* aRequest) {
              aRequest));
         JS::Rooted<JS::Value> error(cx, moduleScript->ErrorToRethrow());
         JS_SetPendingException(cx, error);
-        return NS_OK;  // An error is reported by AutoEntryScript.
+
+        // For a dynamic import, the promise is rejected.  Otherwise an error is
+        // either reported by AutoEntryScript.
+        if (request->IsDynamicImport()) {
+          FinishDynamicImport(cx, request, NS_OK);
+        }
+        return NS_OK;
       }
 
       JS::Rooted<JSObject*> module(cx, moduleScript->ModuleRecord());
@@ -2280,9 +2443,16 @@ nsresult ScriptLoader::EvaluateScript(ScriptLoadRequest* aRequest) {
 
       rv = nsJSUtils::ModuleEvaluate(cx, module);
       MOZ_ASSERT(NS_FAILED(rv) == aes.HasException());
+
       if (NS_FAILED(rv)) {
         LOG(("ScriptLoadRequest (%p):   evaluation failed", aRequest));
-        rv = NS_OK;  // An error is reported by AutoEntryScript.
+        // For a dynamic import, the promise is rejected.  Otherwise an error is
+        // either reported by AutoEntryScript.
+        rv = NS_OK;
+      }
+
+      if (request->IsDynamicImport()) {
+        FinishDynamicImport(cx, request, rv);
       }
 
       aRequest->mCacheInfo = nullptr;
@@ -2354,8 +2524,7 @@ nsresult ScriptLoader::EvaluateScript(ScriptLoadRequest* aRequest) {
 
           // Queue the current script load request to later save the bytecode.
           if (script && encodeBytecode) {
-            aRequest->mScript = script;
-            HoldJSObjects(aRequest);
+            aRequest->SetScript(script);
             TRACE_FOR_TEST(aRequest->Element(), "scriptloader_encode");
             MOZ_ASSERT(aRequest->mBytecodeOffset ==
                        aRequest->mScriptBytecode.length());
@@ -2379,7 +2548,6 @@ nsresult ScriptLoader::EvaluateScript(ScriptLoadRequest* aRequest) {
     MaybeTriggerBytecodeEncoding();
   }
 
-  context->SetProcessingScriptTag(oldProcessingScriptTag);
   return rv;
 }
 
@@ -2567,7 +2735,8 @@ bool ScriptLoader::HasPendingRequests() {
   return mParserBlockingRequest || !mXSLTRequests.isEmpty() ||
          !mLoadedAsyncRequests.isEmpty() ||
          !mNonAsyncExternalScriptInsertedRequests.isEmpty() ||
-         !mDeferRequests.isEmpty() || !mPendingChildLoaders.IsEmpty();
+         !mDeferRequests.isEmpty() || !mDynamicImportRequests.isEmpty() ||
+         !mPendingChildLoaders.IsEmpty();
 }
 
 void ScriptLoader::ProcessPendingRequestsAsync() {
@@ -2980,12 +3149,31 @@ void ScriptLoader::HandleLoadError(ScriptLoadRequest* aRequest,
       RefPtr<ScriptLoadRequest> req = mXSLTRequests.Steal(aRequest);
       FireScriptAvailable(aResult, req);
     }
-  } else if (aRequest->IsModuleRequest() && !aRequest->IsPreload()) {
+  } else if (aRequest->IsPreload()) {
+    if (aRequest->IsModuleRequest()) {
+      aRequest->Cancel();
+    }
+    if (aRequest->IsTopLevel()) {
+      MOZ_ALWAYS_TRUE(
+          mPreloads.RemoveElement(aRequest, PreloadRequestComparator()));
+    }
+    MOZ_ASSERT(!aRequest->isInList());
+    AccumulateCategorical(LABELS_DOM_SCRIPT_PRELOAD_RESULT::LoadError);
+  } else if (aRequest->IsModuleRequest()) {
     ModuleLoadRequest* modReq = aRequest->AsModuleRequest();
-    MOZ_ASSERT(!modReq->IsTopLevel());
-    MOZ_ASSERT(!modReq->isInList());
-    modReq->Cancel();
-    // A single error is fired for the top level module.
+    if (modReq->IsDynamicImport()) {
+      MOZ_ASSERT(modReq->IsTopLevel());
+      if (aRequest->isInList()) {
+        RefPtr<ScriptLoadRequest> req = mDynamicImportRequests.Steal(aRequest);
+        modReq->Cancel();
+        FinishDynamicImport(modReq, aResult);
+      }
+    } else {
+      MOZ_ASSERT(!modReq->IsTopLevel());
+      MOZ_ASSERT(!modReq->isInList());
+      modReq->Cancel();
+      // The error is handled for the top level module.
+    }
   } else if (mParserBlockingRequest == aRequest) {
     MOZ_ASSERT(!aRequest->isInList());
     mParserBlockingRequest = nullptr;
@@ -3000,16 +3188,6 @@ void ScriptLoader::HandleLoadError(ScriptLoadRequest* aRequest,
     FireScriptAvailable(aResult, aRequest);
     ContinueParserAsync(aRequest);
     mCurrentParserInsertedScript = oldParserInsertedScript;
-  } else if (aRequest->IsPreload()) {
-    if (aRequest->IsModuleRequest()) {
-      aRequest->Cancel();
-    }
-    if (aRequest->IsTopLevel()) {
-      MOZ_ALWAYS_TRUE(
-          mPreloads.RemoveElement(aRequest, PreloadRequestComparator()));
-    }
-    MOZ_ASSERT(!aRequest->isInList());
-    AccumulateCategorical(LABELS_DOM_SCRIPT_PRELOAD_RESULT::LoadError);
   } else {
     // This happens for blocking requests cancelled by ParsingComplete().
     MOZ_ASSERT(aRequest->IsCanceled());
@@ -3110,11 +3288,12 @@ nsresult ScriptLoader::PrepareLoadedRequest(ScriptLoadRequest* aRequest,
                    mLoadingAsyncRequests.Contains(aRequest) ||
                    mNonAsyncExternalScriptInsertedRequests.Contains(aRequest) ||
                    mXSLTRequests.Contains(aRequest) ||
+                   mDynamicImportRequests.Contains(aRequest) ||
                    (aRequest->IsModuleRequest() &&
                     !aRequest->AsModuleRequest()->IsTopLevel() &&
                     !aRequest->isInList()) ||
                    mPreloads.Contains(aRequest, PreloadRequestComparator()) ||
-                   mParserBlockingRequest,
+                   mParserBlockingRequest == aRequest,
                "aRequest should be pending!");
 
   if (aRequest->IsModuleRequest()) {
@@ -3191,6 +3370,13 @@ void ScriptLoader::ParsingComplete(bool aTerminated) {
     mLoadedAsyncRequests.Clear();
     mNonAsyncExternalScriptInsertedRequests.Clear();
     mXSLTRequests.Clear();
+
+    for (ScriptLoadRequest* req = mDynamicImportRequests.getFirst(); req;
+         req = req->getNext()) {
+      req->Cancel();
+      FinishDynamicImport(req->AsModuleRequest(), NS_ERROR_ABORT);
+    }
+
     if (mParserBlockingRequest) {
       mParserBlockingRequest->Cancel();
       mParserBlockingRequest = nullptr;
diff --git a/dom/script/ScriptLoader.h b/dom/script/ScriptLoader.h
index f1c80dac353f..a149969e269c 100644
--- a/dom/script/ScriptLoader.h
+++ b/dom/script/ScriptLoader.h
@@ -310,9 +310,16 @@ class ScriptLoader final : public nsISupports {
    */
   void Destroy() { GiveUpBytecodeEncoding(); }
 
+  void StartDynamicImport(ModuleLoadRequest* aRequest);
+  void FinishDynamicImport(ModuleLoadRequest* aRequest, nsresult aResult);
+  void FinishDynamicImport(JSContext* aCx, ModuleLoadRequest* aRequest,
+                           nsresult aResult);
+
  private:
   virtual ~ScriptLoader();
 
+  void EnsureModuleHooksInitialized();
+
   ScriptLoadRequest* CreateLoadRequest(
       ScriptKind aKind, nsIURI* aURI, nsIScriptElement* aElement,
       nsIPrincipal* aTriggeringPrincipal, mozilla::CORSMode aCORSMode,
@@ -419,6 +426,7 @@ class ScriptLoader final : public nsISupports {
   nsresult AttemptAsyncScriptCompile(ScriptLoadRequest* aRequest,
                                      bool* aCouldCompileOut);
   nsresult ProcessRequest(ScriptLoadRequest* aRequest);
+  void ProcessDynamicImport(ModuleLoadRequest* aRequest);
   nsresult CompileOffThreadOrProcessRequest(ScriptLoadRequest* aRequest);
   void FireScriptAvailable(nsresult aResult, ScriptLoadRequest* aRequest);
   void FireScriptEvaluated(nsresult aResult, ScriptLoadRequest* aRequest);
@@ -500,6 +508,8 @@ class ScriptLoader final : public nsISupports {
   nsresult AssociateSourceElementsForModuleTree(JSContext* aCx,
                                                 ModuleLoadRequest* aRequest);
 
+  void RunScriptWhenSafe(ScriptLoadRequest* aRequest);
+
   nsIDocument* mDocument;  // [WEAK]
   nsCOMArray<nsIScriptLoaderObserver> mObservers;
   ScriptLoadRequestList mNonAsyncExternalScriptInsertedRequests;
@@ -509,6 +519,7 @@ class ScriptLoader final : public nsISupports {
   ScriptLoadRequestList mLoadedAsyncRequests;
   ScriptLoadRequestList mDeferRequests;
   ScriptLoadRequestList mXSLTRequests;
+  ScriptLoadRequestList mDynamicImportRequests;
   RefPtr<ScriptLoadRequest> mParserBlockingRequest;
 
   // List of script load request that are holding a buffer which has to be saved
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 9f1fe6b07802..7d01fcfc9efd 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -1584,6 +1584,9 @@ pref("javascript.options.streams", true);
 // BigInt API
 pref("javascript.options.bigint", false);
 
+// Dynamic module import.
+pref("javascript.options.dynamicImport", false);
+
 // advanced prefs
 pref("advanced.mailftp",                    false);
 pref("image.animation_mode",                "normal");
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/__dir__.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/__dir__.ini
index d5dac143ee80..6d005f1193bf 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/__dir__.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/__dir__.ini
@@ -1 +1,2 @@
 lsan-allowed: [Init, nsHostResolver::ResolveHost]
+prefs: [javascript.options.dynamicImport:true, security.csp.experimentalEnabled:true]
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/dynamic-imports.html.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/dynamic-imports.html.ini
index 97bc199dc183..286fd3782a40 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/dynamic-imports.html.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/dynamic-imports.html.ini
@@ -2,6 +2,3 @@
   [Basic dynamic imports]
     expected: FAIL
 
-  [Dynamic imports should resolve module.]
-    expected: FAIL
-
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/inline-event-handler.html.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/inline-event-handler.html.ini
index dc7605982e3c..8419b539ddfa 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/inline-event-handler.html.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/inline-event-handler.html.ini
@@ -1,5 +1,5 @@
 [inline-event-handler.html]
-  expected: ERROR
+  expected: TIMEOUT
   [dynamic import should work when triggered from inline event handlers]
     expected: TIMEOUT
 
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/propagate-nonce-external-module.html.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/propagate-nonce-external-module.html.ini
index 88d159d15bba..818585792380 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/propagate-nonce-external-module.html.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/propagate-nonce-external-module.html.ini
@@ -5,6 +5,3 @@
   [propagate-nonce-external-module]
     expected: FAIL
 
-  [Dynamically imported module should eval when imported from script w/ a valid nonce.]
-    expected: FAIL
-
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/propagate-nonce-inline-module.html.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/propagate-nonce-inline-module.html.ini
index 5d5e41b493b1..1ae15b2cb1f3 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/propagate-nonce-inline-module.html.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/propagate-nonce-inline-module.html.ini
@@ -5,6 +5,3 @@
   [propagate-nonce-inline-module]
     expected: FAIL
 
-  [Dynamically imported module should eval when imported from script w/ a valid nonce.]
-    expected: FAIL
-
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-external-classic.html.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-external-classic.html.ini
index 561a853ef04a..8e4b5e1742a5 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-external-classic.html.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-external-classic.html.ini
@@ -1,17 +1,16 @@
 [string-compilation-base-url-external-classic.html]
-  expected: ERROR
   [setTimeout should successfully import]
-    expected: TIMEOUT
+    expected: FAIL
 
   [eval should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
   [Function should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
   [reflected-inline-event-handlers should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
   [inline-event-handlers-UA-code should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-external-module.html.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-external-module.html.ini
index 8ab45e81277f..47778afc3927 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-external-module.html.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-external-module.html.ini
@@ -1,17 +1,10 @@
 [string-compilation-base-url-external-module.html]
-  expected: ERROR
   [setTimeout should successfully import]
-    expected: TIMEOUT
-
-  [eval should successfully import]
-    expected: NOTRUN
-
-  [Function should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
   [reflected-inline-event-handlers should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
   [inline-event-handlers-UA-code should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-inline-classic.html.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-inline-classic.html.ini
index 15e1bfdbcdb5..940a7b9ebef7 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-inline-classic.html.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-inline-classic.html.ini
@@ -1,17 +1,16 @@
 [string-compilation-base-url-inline-classic.html]
-  expected: ERROR
   [setTimeout should successfully import]
-    expected: TIMEOUT
+    expected: FAIL
 
   [eval should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
   [the Function constructor should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
   [reflected inline event handlers should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
   [inline event handlers triggered via UA code should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-inline-module.html.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-inline-module.html.ini
index f8de16854935..a981230b492e 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-inline-module.html.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-base-url-inline-module.html.ini
@@ -1,17 +1,10 @@
 [string-compilation-base-url-inline-module.html]
-  expected: ERROR
   [setTimeout should successfully import]
-    expected: TIMEOUT
-
-  [eval should successfully import]
-    expected: NOTRUN
-
-  [the Function constructor should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
   [reflected inline event handlers should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
   [inline event handlers triggered via UA code should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-classic.html.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-classic.html.ini
index 314d87f7c31d..0fe906742db6 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-classic.html.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-classic.html.ini
@@ -1,17 +1,16 @@
 [string-compilation-classic.html]
-  expected: ERROR
   [eval should successfully import]
     expected: FAIL
 
   [setTimeout should successfully import]
-    expected: TIMEOUT
+    expected: FAIL
 
   [the Function constructor should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
   [reflected inline event handlers should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
   [inline event handlers triggered via UA code should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-module.html.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-module.html.ini
index 4824d628f8ef..5437bff6ed7c 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-module.html.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-module.html.ini
@@ -1,17 +1,10 @@
 [string-compilation-module.html]
-  expected: ERROR
-  [eval should successfully import]
+  [setTimeout should successfully import]
     expected: FAIL
 
-  [setTimeout should successfully import]
-    expected: TIMEOUT
-
-  [the Function constructor should successfully import]
-    expected: NOTRUN
-
   [reflected inline event handlers should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
   [inline event handlers triggered via UA code should successfully import]
-    expected: NOTRUN
+    expected: FAIL
 
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-nonce-classic.html.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-nonce-classic.html.ini
index 2432b79d4611..a95f8c1be910 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-nonce-classic.html.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-nonce-classic.html.ini
@@ -1,20 +1,19 @@
 [string-compilation-nonce-classic.html]
-  expected: ERROR
   [setTimeout must inherit the nonce from the triggering script, thus execute]
-    expected: TIMEOUT
+    expected: FAIL
 
   [direct eval must inherit the nonce from the triggering script, thus execute]
-    expected: NOTRUN
+    expected: FAIL
 
   [indirect eval must inherit the nonce from the triggering script, thus execute]
-    expected: NOTRUN
+    expected: FAIL
 
   [the Function constructor must inherit the nonce from the triggering script, thus execute]
-    expected: NOTRUN
+    expected: FAIL
 
   [reflected inline event handlers must inherit the nonce from the triggering script, thus execute]
-    expected: NOTRUN
+    expected: FAIL
 
   [inline event handlers triggered via UA code must inherit the nonce from the triggering script, thus execute]
-    expected: NOTRUN
+    expected: FAIL
 
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-nonce-module.html.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-nonce-module.html.ini
index 71533eeb57ae..09434b9b0e3a 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-nonce-module.html.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-nonce-module.html.ini
@@ -1,20 +1,10 @@
 [string-compilation-nonce-module.html]
-  expected: ERROR
   [setTimeout must inherit the nonce from the triggering script, thus execute]
-    expected: TIMEOUT
-
-  [direct eval must inherit the nonce from the triggering script, thus execute]
-    expected: NOTRUN
-
-  [indirect eval must inherit the nonce from the triggering script, thus execute]
-    expected: NOTRUN
-
-  [the Function constructor must inherit the nonce from the triggering script, thus execute]
-    expected: NOTRUN
+    expected: FAIL
 
   [reflected inline event handlers must inherit the nonce from the triggering script, thus execute]
-    expected: NOTRUN
+    expected: FAIL
 
   [inline event handlers triggered via UA code must inherit the nonce from the triggering script, thus execute]
-    expected: NOTRUN
+    expected: FAIL
 
diff --git a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-of-promise-result.html.ini b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-of-promise-result.html.ini
index 3a95d9aaff49..588cf57c9df9 100644
--- a/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-of-promise-result.html.ini
+++ b/testing/web-platform/meta/html/semantics/scripting-1/the-script-element/module/dynamic-import/string-compilation-of-promise-result.html.ini
@@ -2,12 +2,6 @@
   [Evaled the script via eval, successful import]
     expected: FAIL
 
-  [Evaled the script via eval, failed import]
-    expected: FAIL
-
   [Evaled the script via Function, successful import]
     expected: FAIL
 
-  [Evaled the script via Function, failed import]
-    expected: FAIL
-