Index: Python/ceval.c
===================================================================
--- Python/ceval.c	(revision 62050)
+++ Python/ceval.c	(working copy)
@@ -3650,10 +3650,23 @@
 		if (PyMethod_Check(func) && PyMethod_GET_SELF(func) != NULL) {
 			/* optimize access to bound methods */
 			PyObject *self = PyMethod_GET_SELF(func);
+			PyObject *mfunc = PyMethod_GET_FUNCTION(func);
+			PyCodeObject *co = (PyCodeObject *)PyFunction_GET_CODE(mfunc);
+			if (PyFunction_GET_DEFAULTS(mfunc) == NULL &&
+			    !(co->co_flags & CO_VARARGS) &&
+			    nk == 0 && co->co_argcount != na+1) {
+			  PyErr_Format(PyExc_TypeError, "<%s object>.%s()"
+				       " takes exactly %d arguments (%d given)",
+				       Py_TYPE(self)->tp_name,
+				       PyString_AS_STRING(((PyFunctionObject*)mfunc)->func_name),
+				       co->co_argcount-1, na);
+			  x = NULL;
+			  goto error;
+			}
 			PCALL(PCALL_METHOD);
 			PCALL(PCALL_BOUND_METHOD);
 			Py_INCREF(self);
-			func = PyMethod_GET_FUNCTION(func);
+			func = mfunc;
 			Py_INCREF(func);
 			Py_DECREF(*pfunc);
 			*pfunc = self;
@@ -3674,6 +3687,7 @@
            the arguments in case they weren't consumed already
            (fast_function() and err_args() leave them on the stack).
 	 */
+ error:
 	while ((*pp_stack) > pfunc) {
 		w = EXT_POP(*pp_stack);
 		Py_DECREF(w);