diff --git a/js/src/jsparse.c b/js/src/jsparse.c
index ff1a85c61002..2f3fe907802d 100644
--- a/js/src/jsparse.c
+++ b/js/src/jsparse.c
@@ -2804,18 +2804,20 @@ Statement(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc)
             if (TOKEN_TYPE_IS_DECL(tt)
                 ? (pn1->pn_count > 1 || pn1->pn_op == JSOP_DEFCONST
 #if JS_HAS_DESTRUCTURING
-                   || pn1->pn_head->pn_type == TOK_RC
-                   || (pn1->pn_head->pn_type == TOK_RB &&
-                       pn1->pn_head->pn_count != 2)
-                   || (pn1->pn_head->pn_type == TOK_ASSIGN &&
-                       (pn1->pn_head->pn_left->pn_type != TOK_RB ||
-                        pn1->pn_head->pn_left->pn_count != 2))
+                   || (pn->pn_op == JSOP_FORIN &&
+                       (pn1->pn_head->pn_type == TOK_RC ||
+                        (pn1->pn_head->pn_type == TOK_RB &&
+                         pn1->pn_head->pn_count != 2) ||
+                        (pn1->pn_head->pn_type == TOK_ASSIGN &&
+                         (pn1->pn_head->pn_left->pn_type != TOK_RB ||
+                          pn1->pn_head->pn_left->pn_count != 2))))
 #endif
                   )
                 : (pn1->pn_type != TOK_NAME &&
                    pn1->pn_type != TOK_DOT &&
 #if JS_HAS_DESTRUCTURING
-                   (pn1->pn_type != TOK_RB || pn1->pn_count != 2) &&
+                   (pn->pn_op == JSOP_FORIN &&
+                    (pn1->pn_type != TOK_RB || pn1->pn_count != 2)) &&
 #endif
 #if JS_HAS_LVALUE_RETURN
                    pn1->pn_type != TOK_LP &&