diff --git a/runtime/ClassLoaderWrapper.cs b/runtime/ClassLoaderWrapper.cs
index 3a2db203..34931633 100644
--- a/runtime/ClassLoaderWrapper.cs
+++ b/runtime/ClassLoaderWrapper.cs
@@ -468,7 +468,15 @@ namespace IKVM.Internal
 			{
 				wrapper = (TypeWrapper)types[name];
 			}
-			if(wrapper == null)
+			if(wrapper != null)
+			{
+				if(wrapper.TypeAsTBD != type)
+				{
+					string msg = String.Format("\nTypename \"{0}\" is imported from multiple assemblies:\n{1}\n{2}\n", type.FullName, wrapper.Assembly.FullName, type.Assembly.FullName);
+					JVM.CriticalFailure(msg, null);
+				}
+			}
+			else
 			{
 				if(javaType)
 				{
diff --git a/runtime/TypeWrapper.cs b/runtime/TypeWrapper.cs
index c7481ed7..e8df9aef 100644
--- a/runtime/TypeWrapper.cs
+++ b/runtime/TypeWrapper.cs
@@ -1521,6 +1521,35 @@ namespace IKVM.Internal
 			}
 			if(mce != null)
 			{
+				if(mce.DeclaringType != wrapper)
+				{
+					// check the loader constraints
+					bool error = false;
+					if(mce.ReturnType != ifmethod.ReturnType)
+					{
+						// TODO handle unloadable
+						error = true;
+					}
+					TypeWrapper[] mceparams = mce.GetParameters();
+					TypeWrapper[] ifparams = ifmethod.GetParameters();
+					for(int i = 0; i < mceparams.Length; i++)
+					{
+						if(mceparams[i] != ifparams[i])
+						{
+							// TODO handle unloadable
+							error = true;
+							break;
+						}
+					}
+					if(error)
+					{
+						MethodBuilder mb = typeBuilder.DefineMethod(mangledName, MethodAttributes.NewSlot | MethodAttributes.Private | MethodAttributes.Virtual | MethodAttributes.Final, ifmethod.ReturnTypeForDefineMethod, ifmethod.GetParametersForDefineMethod());
+						AttributeHelper.HideFromJava(mb);
+						EmitHelper.Throw(mb.GetILGenerator(), "java.lang.LinkageError", wrapper.Name + "." + ifmethod.Name + ifmethod.Signature);
+						typeBuilder.DefineMethodOverride(mb, (MethodInfo)ifmethod.GetMethod());
+						return;
+					}
+				}
 				if(mce.IsMirandaMethod && mce.DeclaringType == wrapper)
 				{
 					// Miranda methods already have a methodimpl (if needed) to implement the correct interface method
diff --git a/runtime/classpath.cs b/runtime/classpath.cs
index 0c616468..f82f6f00 100644
--- a/runtime/classpath.cs
+++ b/runtime/classpath.cs
@@ -618,16 +618,23 @@ namespace IKVM.NativeCode.java
 
 			public static string getPackageName(Type type)
 			{
-				// TODO consider optimizing this (by getting the type name without constructing the TypeWrapper)
-				string name = ClassLoaderWrapper.GetWrapperFromType(type).Name;
-				// if we process mscorlib and we encounter a primitive, the name will be null
-				if(name != null)
+				string name;
+				if(type.Assembly is System.Reflection.Emit.AssemblyBuilder)
 				{
-					int dot = name.LastIndexOf('.');
-					if(dot > 0)
-					{
-						return name.Substring(0, dot);
-					}
+					name = ClassLoaderWrapper.GetWrapperFromType(type).Name;
+				}
+				else if(type.Module.IsDefined(typeof(JavaModuleAttribute), false))
+				{
+					name = CompiledTypeWrapper.GetName(type);
+				}
+				else
+				{
+					name = DotNetTypeWrapper.GetName(type);
+				}
+				int dot = name.LastIndexOf('.');
+				if(dot > 0)
+				{
+					return name.Substring(0, dot);
 				}
 				return null;
 			}