diff --git a/src/AssemblyGenerator.Attributes.cs b/src/AssemblyGenerator.Attributes.cs
index 20187b7..2dcc2a5 100644
--- a/src/AssemblyGenerator.Attributes.cs
+++ b/src/AssemblyGenerator.Attributes.cs
@@ -55,7 +55,7 @@ static void EncodeLiteral(LiteralEncoder litEnc, CustomAttributeTypedArgument ar
             if (arg.Value is Type type)
             {
                 // Type reference
-                litEnc.Scalar().SystemType(type.FullName);
+                litEnc.Scalar().SystemType(type.AssemblyQualifiedName);
             }
             else if (arg.Value is ReadOnlyCollection<CustomAttributeTypedArgument> array)
             {
@@ -162,4 +162,4 @@ static PrimitiveSerializationTypeCode PrimitiveTypeCodeFromSystemTypeCode(Type t
             throw new NotImplementedException($"Unsupported primitive type: {type}");
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/Metadata/AssemblyMetadata.Types.cs b/src/Metadata/AssemblyMetadata.Types.cs
index 0b63551..72b023c 100644
--- a/src/Metadata/AssemblyMetadata.Types.cs
+++ b/src/Metadata/AssemblyMetadata.Types.cs
@@ -24,7 +24,7 @@ public bool IsReferencedType(Type type)
 
             // todo, also maybe in Module, ModuleRef, AssemblyRef and TypeRef
             // ECMA-335 page 273-274
-            return type.Assembly != SourceAssembly;
+            return !SourceAssembly.FullName.Equals(type.Assembly.FullName);
         }
 
         private EntityHandle ResolveTypeReference(Type type)
@@ -141,4 +141,4 @@ private StringHandle GetNamespaceForType(Type type)
             return type.IsNested ? default : GetOrAddString(type.Namespace);
         }
     }
-}
\ No newline at end of file
+}