diff --git a/src/Core/Parser/ASTConverter.cs b/src/Core/Parser/ASTConverter.cs
index 593c9a3c..f66bc2d0 100644
--- a/src/Core/Parser/ASTConverter.cs
+++ b/src/Core/Parser/ASTConverter.cs
@@ -619,7 +619,7 @@ namespace CppSharp
             if (decl == null)
                 return null;
 
-            if (decl.OriginalPtr == null)
+            if (decl.OriginalPtr == IntPtr.Zero)
                 throw new NotSupportedException("Original pointer must not be null");
 
             var originalPtr = decl.OriginalPtr;
diff --git a/src/Generator.Tests/AST/TestAST.cs b/src/Generator.Tests/AST/TestAST.cs
index 99445547..c1f9ddd8 100644
--- a/src/Generator.Tests/AST/TestAST.cs
+++ b/src/Generator.Tests/AST/TestAST.cs
@@ -9,8 +9,6 @@ namespace CppSharp.Generator.Tests.AST
     [TestFixture]
     public class TestAST : ASTTestFixture
     {
-        private PassBuilder<TranslationUnitPass> passBuilder;
-
         [TestFixtureSetUp]
         public void Init()
         {
@@ -20,7 +18,6 @@ namespace CppSharp.Generator.Tests.AST
         public void Setup()
         {
             ParseLibrary("AST.h", "ASTExtensions.h");
-            passBuilder = new PassBuilder<TranslationUnitPass>(Driver);
         }
 
         [Test]
diff --git a/src/Generator/AST/VTables.cs b/src/Generator/AST/VTables.cs
index 040cf740..31a7689b 100644
--- a/src/Generator/AST/VTables.cs
+++ b/src/Generator/AST/VTables.cs
@@ -12,11 +12,13 @@ namespace CppSharp.AST
             {
             case CppAbi.Microsoft:
                 return GatherVTableMethodsMS(@class);
-            default:
+            case CppAbi.Itanium:
                 return GatherVTableMethodsItanium(@class);
             }
 
-            throw new NotSupportedException();
+            throw new NotSupportedException(
+                string.Format("VTable format for {0} is not supported", @class.Layout.ABI.ToString().Split('.').Last())
+            );
         }
 
         private static List<VTableComponent> GatherVTableMethodEntries(VTableLayout layout)