diff --git a/mozilla/js/src/jsregexp.c b/mozilla/js/src/jsregexp.c
index 6da14d48f61..2cea2dc2931 100644
--- a/mozilla/js/src/jsregexp.c
+++ b/mozilla/js/src/jsregexp.c
@@ -4308,10 +4308,12 @@ js_NewRegExpObject(JSContext *cx, JSTokenStream *ts,
     str = js_NewStringCopyN(cx, chars, length);
     if (!str)
         return NULL;
-    re = js_NewRegExp(cx, ts,  str, flags, JS_FALSE);
-    if (!re)
-        return NULL;
     JS_PUSH_TEMP_ROOT_STRING(cx, str, &tvr);
+    re = js_NewRegExp(cx, ts,  str, flags, JS_FALSE);
+    if (!re) {
+        JS_POP_TEMP_ROOT(cx, &tvr);
+        return NULL;
+    }
     obj = js_NewObject(cx, &js_RegExpClass, NULL, NULL, 0);
     if (!obj || !JS_SetPrivate(cx, obj, re)) {
         js_DestroyRegExp(cx, re);