diff --git a/src/flags/flag-definitions.h b/src/flags/flag-definitions.h
index 6e667d1d2277..37f78d340dd7 100644
--- a/src/flags/flag-definitions.h
+++ b/src/flags/flag-definitions.h
@@ -278,7 +278,8 @@ DEFINE_BOOL(js_shipping, true, "enable all shipped JavaScript features")
 
 // Features that are complete (but still behind the --harmony flag).
 #define HARMONY_STAGED_BASE(V)                  \
-  V(harmony_set_methods, "harmony Set Methods")
+  V(harmony_set_methods, "harmony Set Methods") \
+  V(harmony_iterator_helpers, "JavaScript iterator helpers")
 
 #define JAVASCRIPT_STAGED_FEATURES_BASE(V) \
   V(js_promise_withresolvers, "Promise.withResolvers")
@@ -303,8 +304,7 @@ DEFINE_WEAK_IMPLICATION(harmony_rab_gsab_transfer, harmony_rab_gsab)
   V(harmony_regexp_unicode_sets, "harmony RegExp Unicode Sets")        \
   V(harmony_json_parse_with_source, "harmony json parse with source")  \
   V(harmony_rab_gsab_transfer, "harmony ArrayBuffer.transfer")         \
-  V(harmony_array_grouping, "harmony array grouping")                  \
-  V(harmony_iterator_helpers, "JavaScript iterator helpers")
+  V(harmony_array_grouping, "harmony array grouping")
 
 #define JAVASCRIPT_SHIPPING_FEATURES_BASE(V)
 
diff --git a/test/mjsunit/es6/iterator-prototype.js b/test/mjsunit/es6/iterator-prototype.js
index 82277d981702..496b67de122a 100644
--- a/test/mjsunit/es6/iterator-prototype.js
+++ b/test/mjsunit/es6/iterator-prototype.js
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// Flags: --harmony-iterator-helpers
+
 var arrayIteratorPrototype = [].entries().__proto__;
 var iteratorPrototype = arrayIteratorPrototype.__proto__;
 
diff --git a/test/mozilla/mozilla.status b/test/mozilla/mozilla.status
index 724252d34e0c..aacb4e223352 100644
--- a/test/mozilla/mozilla.status
+++ b/test/mozilla/mozilla.status
@@ -546,6 +546,7 @@
 
   # Uses Mozilla-specific QName, XML, XMLList and Iterator.
   'js1_5/Regress/regress-407323': [FAIL_OK],
+  'js1_5/Regress/regress-407957': [FAIL_OK],
 
 
   # Relies on JavaScript 1.2 / 1.3 deprecated features.