don't return from main loop when error occurs
diff --git a/Python/ceval.c b/Python/ceval.c
index be1e174..35c8998 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1535,7 +1535,8 @@
 					else {
 						err_setstr(TypeError,
 	   "unbound method must be called with class instance 1st argument");
-						return NULL;
+						x = NULL;
+						break;
 					}
 				}
 			}