diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index b33b21c..6f5323e 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -3143,8 +3143,10 @@
 
 	/* Initialize tp_base (defaults to BaseObject unless that's us) */
 	base = type->tp_base;
-	if (base == NULL && type != &PyBaseObject_Type)
+	if (base == NULL && type != &PyBaseObject_Type) {
 		base = type->tp_base = &PyBaseObject_Type;
+		Py_INCREF(base);
+	}
 
 	/* Initialize the base class */
 	if (base && base->tp_dict == NULL) {