Index: src/org/python/core/PyJavaType.java
===================================================================
--- src/org/python/core/PyJavaType.java	(revision 6295)
+++ src/org/python/core/PyJavaType.java	(working copy)
@@ -510,7 +510,7 @@
                 @Override
                 public PyObject __call__(PyObject o) {
                     Object proxy = self.getJavaProxy();
-                    Object oAsJava = o.__tojava__(proxy.getClass());
+                    Object oAsJava = o.__tojava__(Object.class);
                     return proxy.equals(oAsJava) ? Py.True : Py.False;
                 }
             });