diff --git a/src/Main/Base/Project/Src/Dom/CecilReader.cs b/src/Main/Base/Project/Src/Dom/CecilReader.cs
index e480bb405f..414caa9258 100644
--- a/src/Main/Base/Project/Src/Dom/CecilReader.cs
+++ b/src/Main/Base/Project/Src/Dom/CecilReader.cs
@@ -57,6 +57,10 @@ namespace ICSharpCode.SharpDevelop.Dom
 			while (type is ModType) {
 				type = (type as ModType).ElementType;
 			}
+			if (type == null) {
+				LoggingService.Warn("CecilReader: Null type for: " + member);
+				return VoidReturnType.Instance;
+			}
 			if (type is ReferenceType) {
 				// TODO: Use ByRefRefReturnType
 				return CreateType(pc, member, (type as ReferenceType).ElementType);
diff --git a/src/Main/Base/Project/Src/Project/Items/ProjectItem.cs b/src/Main/Base/Project/Src/Project/Items/ProjectItem.cs
index 178f97704b..6587b9624c 100644
--- a/src/Main/Base/Project/Src/Project/Items/ProjectItem.cs
+++ b/src/Main/Base/Project/Src/Project/Items/ProjectItem.cs
@@ -82,11 +82,7 @@ namespace ICSharpCode.SharpDevelop.Project
 			item.Include = newInclude;
 		}
 		
-		public virtual ProjectItem Clone()
-		{
-			// TODO: Make me abstract in SD 2.1
-			throw new NotSupportedException();
-		}
+		public abstract ProjectItem Clone();
 		
 		object ICloneable.Clone()
 		{