diff --git a/artiq/compiler/embedding.py b/artiq/compiler/embedding.py
index 6910f185e..141d9eca1 100644
--- a/artiq/compiler/embedding.py
+++ b/artiq/compiler/embedding.py
@@ -101,7 +101,7 @@ class ASTSynthesizer:
             if typ in self.type_map:
                 instance_type, constructor_type = self.type_map[typ]
             else:
-                instance_type = types.TInstance("{}.{}".format(typ.__module__, typ.__name__))
+                instance_type = types.TInstance("{}.{}".format(typ.__module__, typ.__qualname__))
                 instance_type.attributes['__objectid__'] = builtins.TInt(types.TValue(32))
 
                 constructor_type = types.TConstructor(instance_type)