diff --git a/Python/modsupport.c b/Python/modsupport.c
index b4640b0..ec85511 100644
--- a/Python/modsupport.c
+++ b/Python/modsupport.c
@@ -520,8 +520,9 @@
 		return -1;
 	}
 	if (!o) {
-		PyErr_SetString(PyExc_TypeError,
-				"PyModule_AddObject() needs non-NULL value");
+		if (!PyErr_Occurred())
+			PyErr_SetString(PyExc_TypeError,
+					"PyModule_AddObject() needs non-NULL value");
 		return -1;
 	}