diff --git a/runtime/ClassLoaderWrapper.cs b/runtime/ClassLoaderWrapper.cs
index f9b8c090..feeb2728 100644
--- a/runtime/ClassLoaderWrapper.cs
+++ b/runtime/ClassLoaderWrapper.cs
@@ -1761,10 +1761,7 @@ namespace IKVM.Internal
 			{
 				if (delegates == null)
 				{
-#pragma warning disable 184
-					// during ikvmc build: warning CS0184: The given expression is never of the provided ('IKVM.Reflection.Emit.AssemblyBuilder') type
-					if (!(assemblyLoader.Assembly is AssemblyBuilder) && assemblyLoader.Assembly.GetManifestResourceInfo("ikvm.exports") != null)
-#pragma warning restore 184
+					if (!(ReflectUtil.IsDynamicAssembly(assemblyLoader.Assembly)) && assemblyLoader.Assembly.GetManifestResourceInfo("ikvm.exports") != null)
 					{
 						List<string> wildcardExports = new List<string>();
 						using (Stream stream = assemblyLoader.Assembly.GetManifestResourceStream("ikvm.exports"))
@@ -2042,6 +2039,10 @@ namespace IKVM.Internal
 #if !STATIC_COMPILER
 		internal Assembly FindResourceAssembliesImpl(string unmangledName, string name, bool firstOnly, ref List<Assembly> list)
 		{
+			if(ReflectUtil.IsDynamicAssembly(assemblyLoader.Assembly))
+			{
+				return null;
+			}
 			if(assemblyLoader.Assembly.GetManifestResourceInfo(name) != null)
 			{
 				if(firstOnly)
@@ -2096,6 +2097,7 @@ namespace IKVM.Internal
 			{
 				return new Assembly[] { first };
 			}
+			LazyInitExports();
 			for(int i = 0; i < delegates.Length; i++)
 			{
 				if(delegates[i] == null)
diff --git a/runtime/DynamicClassLoader.cs b/runtime/DynamicClassLoader.cs
index e7572d4d..25685049 100644
--- a/runtime/DynamicClassLoader.cs
+++ b/runtime/DynamicClassLoader.cs
@@ -427,24 +427,6 @@ namespace IKVM.Internal
 			assemblyBuilder.SetCustomAttribute(debugAttr);
 			return JVM.IsSaveDebugImage ? assemblyBuilder.DefineDynamicModule("ikvmdump.dll", "ikvmdump.dll", debug) : assemblyBuilder.DefineDynamicModule(name.Name, debug);
 		}
-
-		internal static bool IsDynamicAssembly(Assembly asm)
-		{
-#if NET_4_0
-			return asm.IsDynamic();
-#else
-			if (asm is System.Reflection.Emit.AssemblyBuilder)
-			{
-				return true;
-			}
-			if (asm.Equals(Instance.ModuleBuilder.Assembly))
-			{
-				// this can happen on Orcas, where an AssemblyBuilder has a corresponding Assembly
-				return true;
-			}
-			return false;
-#endif
-		}
 #endif // !STATIC_COMPILER
 	}
 }
diff --git a/runtime/ReflectUtil.cs b/runtime/ReflectUtil.cs
index de651bb7..3d8f9a5a 100644
--- a/runtime/ReflectUtil.cs
+++ b/runtime/ReflectUtil.cs
@@ -65,5 +65,17 @@ namespace IKVM.Internal
 			return type.Assembly;
 		}
 #endif
+
+		internal static bool IsDynamicAssembly(Assembly asm)
+		{
+#if NET_4_0
+			return asm.IsDynamic();
+#else
+			// HACK pre-.NET 4.0 there is no API for this
+			string manifest = asm.ManifestModule.Name;
+			return manifest == "<In Memory Module>" 		// .NET name
+				|| manifest == "Default Dynamic Module";	// Mono name
+#endif
+		}
 	}
 }
diff --git a/runtime/common.cs b/runtime/common.cs
index 0db995b8..acdf0b61 100644
--- a/runtime/common.cs
+++ b/runtime/common.cs
@@ -310,7 +310,7 @@ namespace IKVM.NativeCode.ikvm.runtime
 	{
 		public static object loadClassFromAssembly(Assembly asm, string className)
 		{
-			if(DynamicClassLoader.IsDynamicAssembly(asm))
+			if(ReflectUtil.IsDynamicAssembly(asm))
 			{
 				return null;
 			}
@@ -320,7 +320,7 @@ namespace IKVM.NativeCode.ikvm.runtime
 
 		public static bool findResourceInAssembly(Assembly asm, string resourceName)
 		{
-			if(DynamicClassLoader.IsDynamicAssembly(asm))
+			if(ReflectUtil.IsDynamicAssembly(asm))
 			{
 				return false;
 			}