diff --git a/mozilla/js/src/jsparse.c b/mozilla/js/src/jsparse.c
index 039467a112e..7cf18d4548b 100644
--- a/mozilla/js/src/jsparse.c
+++ b/mozilla/js/src/jsparse.c
@@ -2813,8 +2813,9 @@ PrimaryExpr(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc)
                     /* So CURRENT_TOKEN gets TOK_COMMA and not TOK_LB. */
                     js_MatchToken(cx, ts, TOK_COMMA);
                     pn2 = NewParseNode(cx, &CURRENT_TOKEN(ts), PN_NULLARY, tc);
-                } else
+                } else {
                     pn2 = AssignExpr(cx, ts, tc);
+                }
                 if (!pn2)
                     return NULL;
                 PN_APPEND(pn, pn2);