diff --git a/js/src/jsobj.c b/js/src/jsobj.c
index cbc05ca7f61f..79d56bbfc652 100644
--- a/js/src/jsobj.c
+++ b/js/src/jsobj.c
@@ -170,7 +170,8 @@ static JSBool
 obj_setSlot(JSContext *cx, JSObject *obj, jsval id, jsval *vp)
 {
     JSObject *pobj;
-    uint32 slot, attrs;
+    uint32 slot;
+    uintN attrs;
 
     if (!JSVAL_IS_OBJECT(*vp))
         return JS_TRUE;