diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 9c13d9aefb..835ac7a88f 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -2294,7 +2294,6 @@ void Bootstrapper::ExportExperimentalFromRuntime(Isolate* isolate,
   }
 
   INITIALIZE_FLAG(FLAG_harmony_tostring)
-  INITIALIZE_FLAG(FLAG_harmony_tolength)
   INITIALIZE_FLAG(FLAG_harmony_species)
 
 #undef INITIALIZE_FLAG
@@ -2314,8 +2313,6 @@ EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_destructuring_assignment)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_object_observe)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_regexps)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_unicode_regexps)
-EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_completion)
-EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_tolength)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_do_expressions)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_regexp_lookbehind)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_function_name)
@@ -2344,13 +2341,6 @@ void Genesis::InitializeGlobal_harmony_tostring() {
 }
 
 
-void Genesis::InitializeGlobal_harmony_concat_spreadable() {
-  if (!FLAG_harmony_concat_spreadable) return;
-  InstallPublicSymbol(factory(), native_context(), "isConcatSpreadable",
-                      factory()->is_concat_spreadable_symbol());
-}
-
-
 void Genesis::InitializeGlobal_harmony_regexp_subclass() {
   if (!FLAG_harmony_regexp_subclass) return;
   InstallPublicSymbol(factory(), native_context(), "match",
@@ -2948,11 +2938,8 @@ bool Genesis::InstallExperimentalNatives() {
       "native harmony-object-observe.js", nullptr};
   static const char* harmony_sharedarraybuffer_natives[] = {
       "native harmony-sharedarraybuffer.js", "native harmony-atomics.js", NULL};
-  static const char* harmony_concat_spreadable_natives[] = {nullptr};
   static const char* harmony_simd_natives[] = {"native harmony-simd.js",
                                                nullptr};
-  static const char* harmony_tolength_natives[] = {nullptr};
-  static const char* harmony_completion_natives[] = {nullptr};
   static const char* harmony_do_expressions_natives[] = {nullptr};
   static const char* harmony_regexp_subclass_natives[] = {nullptr};
   static const char* harmony_regexp_lookbehind_natives[] = {nullptr};
diff --git a/src/builtins.cc b/src/builtins.cc
index 6b6c4acd09..d1ed05ad06 100644
--- a/src/builtins.cc
+++ b/src/builtins.cc
@@ -1261,7 +1261,6 @@ bool IterateElements(Isolate* isolate, Handle<JSReceiver> receiver,
 
 bool HasConcatSpreadableModifier(Isolate* isolate, Handle<JSArray> obj) {
   DCHECK(isolate->IsFastArrayConstructorPrototypeChainIntact());
-  if (!FLAG_harmony_concat_spreadable) return false;
   Handle<Symbol> key(isolate->factory()->is_concat_spreadable_symbol());
   Maybe<bool> maybe = JSReceiver::HasProperty(obj, key);
   return maybe.FromMaybe(false);
@@ -1271,14 +1270,12 @@ bool HasConcatSpreadableModifier(Isolate* isolate, Handle<JSArray> obj) {
 static Maybe<bool> IsConcatSpreadable(Isolate* isolate, Handle<Object> obj) {
   HandleScope handle_scope(isolate);
   if (!obj->IsJSReceiver()) return Just(false);
-  if (FLAG_harmony_concat_spreadable) {
-    Handle<Symbol> key(isolate->factory()->is_concat_spreadable_symbol());
-    Handle<Object> value;
-    MaybeHandle<Object> maybeValue =
-        i::Runtime::GetObjectProperty(isolate, obj, key);
-    if (!maybeValue.ToHandle(&value)) return Nothing<bool>();
-    if (!value->IsUndefined()) return Just(value->BooleanValue());
-  }
+  Handle<Symbol> key(isolate->factory()->is_concat_spreadable_symbol());
+  Handle<Object> value;
+  MaybeHandle<Object> maybeValue =
+      i::Runtime::GetObjectProperty(isolate, obj, key);
+  if (!maybeValue.ToHandle(&value)) return Nothing<bool>();
+  if (!value->IsUndefined()) return Just(value->BooleanValue());
   return Object::IsArray(obj);
 }
 
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index ef2f21a86f..1ee05e3963 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -224,11 +224,8 @@ DEFINE_IMPLICATION(es_staging, move_object_start)
   V(harmony_default_parameters, "harmony default parameters")             \
   V(harmony_destructuring_assignment, "harmony destructuring assignment") \
   V(harmony_destructuring_bind, "harmony destructuring bind")             \
-  V(harmony_concat_spreadable, "harmony isConcatSpreadable")              \
   V(harmony_object_observe, "harmony Object.observe")                     \
-  V(harmony_tolength, "harmony ToLength")                                 \
   V(harmony_tostring, "harmony toString")                                 \
-  V(harmony_completion, "harmony completion value semantics")             \
   V(harmony_regexps, "harmony regular expression extensions")             \
   V(harmony_sloppy, "harmony features in sloppy mode")                    \
   V(harmony_sloppy_let, "harmony let in sloppy mode")                     \
diff --git a/src/js/array.js b/src/js/array.js
index f9cf161191..da6e02eded 100644
--- a/src/js/array.js
+++ b/src/js/array.js
@@ -12,7 +12,6 @@
 // Imports
 
 var AddIndexedProperty;
-var FLAG_harmony_tolength;
 var FLAG_harmony_species;
 var GetIterator;
 var GetMethod;
@@ -48,7 +47,6 @@ utils.Import(function(from) {
 });
 
 utils.ImportFromExperimental(function(from) {
-  FLAG_harmony_tolength = from.FLAG_harmony_tolength;
   FLAG_harmony_species = from.FLAG_harmony_species;
 });
 
@@ -431,7 +429,7 @@ function ArrayToString() {
 
 
 function InnerArrayToLocaleString(array, length) {
-  var len = TO_LENGTH_OR_UINT32(length);
+  var len = TO_LENGTH(length);
   if (len === 0) return "";
   return Join(array, len, ',', ConvertToLocaleString);
 }
@@ -469,7 +467,7 @@ function ArrayJoin(separator) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.join");
 
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
 
   return InnerArrayJoin(separator, array, length);
 }
@@ -498,7 +496,7 @@ function ArrayPop() {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.pop");
 
   var array = TO_OBJECT(this);
-  var n = TO_LENGTH_OR_UINT32(array.length);
+  var n = TO_LENGTH(array.length);
   if (n == 0) {
     array.length = n;
     return;
@@ -516,7 +514,7 @@ function ArrayPop() {
 
 
 function ObservedArrayPush() {
-  var n = TO_LENGTH_OR_UINT32(this.length);
+  var n = TO_LENGTH(this.length);
   var m = %_ArgumentsLength();
 
   try {
@@ -544,7 +542,7 @@ function ArrayPush() {
     return ObservedArrayPush.apply(this, arguments);
 
   var array = TO_OBJECT(this);
-  var n = TO_LENGTH_OR_UINT32(array.length);
+  var n = TO_LENGTH(array.length);
   var m = %_ArgumentsLength();
 
   // It appears that there is no enforced, absolute limit on the number of
@@ -650,7 +648,7 @@ function ArrayReverse() {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.reverse");
 
   var array = TO_OBJECT(this);
-  var len = TO_LENGTH_OR_UINT32(array.length);
+  var len = TO_LENGTH(array.length);
   var isArray = IS_ARRAY(array);
 
   if (UseSparseVariant(array, len, isArray, len)) {
@@ -685,7 +683,7 @@ function ArrayShift() {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.shift");
 
   var array = TO_OBJECT(this);
-  var len = TO_LENGTH_OR_UINT32(array.length);
+  var len = TO_LENGTH(array.length);
 
   if (len === 0) {
     array.length = 0;
@@ -712,7 +710,7 @@ function ArrayShift() {
 
 
 function ObservedArrayUnshift() {
-  var len = TO_LENGTH_OR_UINT32(this.length);
+  var len = TO_LENGTH(this.length);
   var num_arguments = %_ArgumentsLength();
 
   try {
@@ -739,7 +737,7 @@ function ArrayUnshift(arg1) {  // length == 1
     return ObservedArrayUnshift.apply(this, arguments);
 
   var array = TO_OBJECT(this);
-  var len = TO_LENGTH_OR_UINT32(array.length);
+  var len = TO_LENGTH(array.length);
   var num_arguments = %_ArgumentsLength();
 
   if (len > 0 && UseSparseVariant(array, len, IS_ARRAY(array), len) &&
@@ -763,7 +761,7 @@ function ArraySlice(start, end) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.slice");
 
   var array = TO_OBJECT(this);
-  var len = TO_LENGTH_OR_UINT32(array.length);
+  var len = TO_LENGTH(array.length);
   var start_i = TO_INTEGER(start);
   var end_i = len;
 
@@ -834,7 +832,7 @@ function ComputeSpliceDeleteCount(delete_count, num_arguments, len, start_i) {
 
 function ObservedArraySplice(start, delete_count) {
   var num_arguments = %_ArgumentsLength();
-  var len = TO_LENGTH_OR_UINT32(this.length);
+  var len = TO_LENGTH(this.length);
   var start_i = ComputeSpliceStartIndex(TO_INTEGER(start), len);
   var del_count = ComputeSpliceDeleteCount(delete_count, num_arguments, len,
                                            start_i);
@@ -881,7 +879,7 @@ function ArraySplice(start, delete_count) {
 
   var num_arguments = %_ArgumentsLength();
   var array = TO_OBJECT(this);
-  var len = TO_LENGTH_OR_UINT32(array.length);
+  var len = TO_LENGTH(array.length);
   var start_i = ComputeSpliceStartIndex(TO_INTEGER(start), len);
   var del_count = ComputeSpliceDeleteCount(delete_count, num_arguments, len,
                                            start_i);
@@ -1217,7 +1215,7 @@ function ArraySort(comparefn) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.sort");
 
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   return InnerArraySort(array, length, comparefn);
 }
 
@@ -1248,7 +1246,7 @@ function ArrayFilter(f, receiver) {
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   if (!IS_CALLABLE(f)) throw MakeTypeError(kCalledNonCallable, f);
   var result = ArraySpeciesCreate(array, 0);
   return InnerArrayFilter(f, receiver, array, length, result);
@@ -1274,7 +1272,7 @@ function ArrayForEach(f, receiver) {
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   InnerArrayForEach(f, receiver, array, length);
 }
 
@@ -1301,7 +1299,7 @@ function ArraySome(f, receiver) {
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   return InnerArraySome(f, receiver, array, length);
 }
 
@@ -1325,7 +1323,7 @@ function ArrayEvery(f, receiver) {
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   return InnerArrayEvery(f, receiver, array, length);
 }
 
@@ -1336,7 +1334,7 @@ function ArrayMap(f, receiver) {
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   if (!IS_CALLABLE(f)) throw MakeTypeError(kCalledNonCallable, f);
   var result = ArraySpeciesCreate(array, length);
   var is_array = IS_ARRAY(array);
@@ -1411,7 +1409,7 @@ function InnerArrayIndexOf(array, element, index, length) {
 function ArrayIndexOf(element, index) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.indexOf");
 
-  var length = TO_LENGTH_OR_UINT32(this.length);
+  var length = TO_LENGTH(this.length);
   return InnerArrayIndexOf(this, element, index, length);
 }
 
@@ -1469,7 +1467,7 @@ function InnerArrayLastIndexOf(array, element, index, length, argumentsLength) {
 function ArrayLastIndexOf(element, index) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.lastIndexOf");
 
-  var length = TO_LENGTH_OR_UINT32(this.length);
+  var length = TO_LENGTH(this.length);
   return InnerArrayLastIndexOf(this, element, index, length,
                         %_ArgumentsLength());
 }
@@ -1508,7 +1506,7 @@ function ArrayReduce(callback, current) {
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   return InnerArrayReduce(callback, current, array, length,
                           %_ArgumentsLength());
 }
@@ -1548,7 +1546,7 @@ function ArrayReduceRight(callback, current) {
   // Pull out the length so that side effects are visible before the
   // callback function is checked.
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
   return InnerArrayReduceRight(callback, current, array, length,
                                %_ArgumentsLength());
 }
@@ -1701,7 +1699,7 @@ function ArrayFill(value, start, end) {
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.fill");
 
   var array = TO_OBJECT(this);
-  var length = TO_LENGTH_OR_UINT32(array.length);
+  var length = TO_LENGTH(array.length);
 
   return InnerArrayFill(value, start, end, array, length);
 }
diff --git a/src/js/macros.py b/src/js/macros.py
index 8114469486..94c9b9479b 100644
--- a/src/js/macros.py
+++ b/src/js/macros.py
@@ -114,8 +114,6 @@ macro TO_INTEGER_MAP_MINUS_ZERO(arg) = (%_IsSmi(%IS_VAR(arg)) ? arg : %NumberToI
 macro TO_INT32(arg) = ((arg) | 0);
 macro TO_UINT32(arg) = ((arg) >>> 0);
 macro TO_LENGTH(arg) = (%_ToLength(arg));
-macro TO_LENGTH_OR_UINT32(arg) = (FLAG_harmony_tolength ? TO_LENGTH(arg) : TO_UINT32(arg));
-macro TO_LENGTH_OR_INTEGER(arg) = (FLAG_harmony_tolength ? TO_LENGTH(arg) : TO_INTEGER(arg));
 macro TO_STRING(arg) = (%_ToString(arg));
 macro TO_NUMBER(arg) = (%_ToNumber(arg));
 macro TO_OBJECT(arg) = (%_ToObject(arg));
diff --git a/src/js/regexp.js b/src/js/regexp.js
index fccbca679a..a456952ef3 100644
--- a/src/js/regexp.js
+++ b/src/js/regexp.js
@@ -10,7 +10,6 @@
 // Imports
 
 var ExpandReplacement;
-var FLAG_harmony_tolength;
 var GlobalObject = global.Object;
 var GlobalRegExp = global.RegExp;
 var GlobalRegExpPrototype;
@@ -22,10 +21,6 @@ var replaceSymbol = utils.ImportNow("replace_symbol");
 var searchSymbol = utils.ImportNow("search_symbol");
 var splitSymbol = utils.ImportNow("split_symbol");
 
-utils.ImportFromExperimental(function(from) {
-  FLAG_harmony_tolength = from.FLAG_harmony_tolength;
-});
-
 utils.Import(function(from) {
   ExpandReplacement = from.ExpandReplacement;
   MakeTypeError = from.MakeTypeError;
@@ -176,7 +171,7 @@ function RegExpExecJS(string) {
 
   // Conversion is required by the ES2015 specification (RegExpBuiltinExec
   // algorithm, step 4) even if the value is discarded for non-global RegExps.
-  var i = TO_LENGTH_OR_INTEGER(lastIndex);
+  var i = TO_LENGTH(lastIndex);
 
   var updateLastIndex = REGEXP_GLOBAL(this) || REGEXP_STICKY(this);
   if (updateLastIndex) {
@@ -223,7 +218,7 @@ function RegExpTest(string) {
 
   // Conversion is required by the ES2015 specification (RegExpBuiltinExec
   // algorithm, step 4) even if the value is discarded for non-global RegExps.
-  var i = TO_LENGTH_OR_INTEGER(lastIndex);
+  var i = TO_LENGTH(lastIndex);
 
   if (REGEXP_GLOBAL(this) || REGEXP_STICKY(this)) {
     if (i < 0 || i > string.length) {
diff --git a/src/js/symbol.js b/src/js/symbol.js
index a5d80a6180..0c87a117ee 100644
--- a/src/js/symbol.js
+++ b/src/js/symbol.js
@@ -77,7 +77,7 @@ function SymbolKeyFor(symbol) {
 utils.InstallConstants(GlobalSymbol, [
   // TODO(rossberg): expose when implemented.
   // "hasInstance", hasInstanceSymbol,
-  // "isConcatSpreadable", isConcatSpreadableSymbol,
+  "isConcatSpreadable", isConcatSpreadableSymbol,
   "iterator", iteratorSymbol,
   // TODO(yangguo): expose when implemented.
   // "match", matchSymbol,
diff --git a/src/parsing/rewriter.cc b/src/parsing/rewriter.cc
index 4da60aca18..646e4d532c 100644
--- a/src/parsing/rewriter.cc
+++ b/src/parsing/rewriter.cc
@@ -148,7 +148,7 @@ void Processor::VisitIfStatement(IfStatement* node) {
   is_set_ = is_set_ && set_in_then;
   replacement_ = node;
 
-  if (FLAG_harmony_completion && !is_set_) {
+  if (!is_set_) {
     is_set_ = true;
     replacement_ = AssignUndefinedBefore(node);
   }
@@ -164,7 +164,7 @@ void Processor::VisitIterationStatement(IterationStatement* node) {
   is_set_ = is_set_ && set_after;
   replacement_ = node;
 
-  if (FLAG_harmony_completion && !is_set_) {
+  if (!is_set_) {
     is_set_ = true;
     replacement_ = AssignUndefinedBefore(node);
   }
@@ -208,7 +208,7 @@ void Processor::VisitTryCatchStatement(TryCatchStatement* node) {
   is_set_ = is_set_ && set_in_try;
   replacement_ = node;
 
-  if (FLAG_harmony_completion && !is_set_) {
+  if (!is_set_) {
     is_set_ = true;
     replacement_ = AssignUndefinedBefore(node);
   }
@@ -245,7 +245,7 @@ void Processor::VisitTryFinallyStatement(TryFinallyStatement* node) {
   node->set_try_block(replacement_->AsBlock());
   replacement_ = node;
 
-  if (FLAG_harmony_completion && !is_set_) {
+  if (!is_set_) {
     is_set_ = true;
     replacement_ = AssignUndefinedBefore(node);
   }
@@ -263,7 +263,7 @@ void Processor::VisitSwitchStatement(SwitchStatement* node) {
   is_set_ = is_set_ && set_after;
   replacement_ = node;
 
-  if (FLAG_harmony_completion && !is_set_) {
+  if (!is_set_) {
     is_set_ = true;
     replacement_ = AssignUndefinedBefore(node);
   }
@@ -287,7 +287,7 @@ void Processor::VisitWithStatement(WithStatement* node) {
   node->set_statement(replacement_);
   replacement_ = node;
 
-  if (FLAG_harmony_completion && !is_set_) {
+  if (!is_set_) {
     is_set_ = true;
     replacement_ = AssignUndefinedBefore(node);
   }
diff --git a/test/cctest/cctest.status b/test/cctest/cctest.status
index 5adcdcef21..7f77748e45 100644
--- a/test/cctest/cctest.status
+++ b/test/cctest/cctest.status
@@ -745,6 +745,7 @@
   'test-heap/AddInstructionChangesNewSpacePromotion': [PASS, FAIL],
   'test-api/ExternalWrap': [PASS, FAIL],
   'test-decls/CrossScriptReferencesHarmony': [PASS, FAIL],
+  'test-lockers/IsolateNestedLocking': [PASS, FAIL],
 }],  # ignition == True and arch == arm64
 
 ]
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
index 647315d782..fe577457b0 100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -24517,7 +24517,6 @@ TEST(AbortOnUncaughtExceptionNoAbort) {
 
 
 TEST(AccessCheckedIsConcatSpreadable) {
-  i::FLAG_harmony_concat_spreadable = true;
   v8::Isolate* isolate = CcTest::isolate();
   HandleScope scope(isolate);
   LocalContext env;
diff --git a/test/mjsunit/harmony/array-concat.js b/test/mjsunit/es6/array-concat.js
similarity index 99%
rename from test/mjsunit/harmony/array-concat.js
rename to test/mjsunit/es6/array-concat.js
index cabdf2df08..ec730db58b 100644
--- a/test/mjsunit/harmony/array-concat.js
+++ b/test/mjsunit/es6/array-concat.js
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-concat-spreadable --harmony-proxies --harmony-reflect
+// Flags: --harmony-proxies --harmony-reflect
 
 (function testArrayConcatArity() {
   "use strict";
diff --git a/test/mjsunit/es6/array-length.js b/test/mjsunit/es6/array-length.js
index cc3b88105c..06efe00901 100644
--- a/test/mjsunit/es6/array-length.js
+++ b/test/mjsunit/es6/array-length.js
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-tolength
-
 // Test array functions do not cause infinite loops when length is negative,
 // max_value, etc.
 
diff --git a/test/mjsunit/es6/block-for.js b/test/mjsunit/es6/block-for.js
index c7a23e8d32..d953d376f0 100644
--- a/test/mjsunit/es6/block-for.js
+++ b/test/mjsunit/es6/block-for.js
@@ -25,8 +25,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --harmony-completion
-
 "use strict";
 
 function props(x) {
diff --git a/test/mjsunit/harmony/completion.js b/test/mjsunit/es6/completion.js
similarity index 98%
rename from test/mjsunit/harmony/completion.js
rename to test/mjsunit/es6/completion.js
index ceeafb2b3d..05565bfb45 100644
--- a/test/mjsunit/harmony/completion.js
+++ b/test/mjsunit/es6/completion.js
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-completion --harmony-sloppy-let --no-legacy-const
+// Flags: --harmony-sloppy-let --no-legacy-const
 
 
 function assertUndef(x) {
diff --git a/test/mjsunit/es6/regexp-tolength.js b/test/mjsunit/es6/regexp-tolength.js
index d9e967ba27..f7cfe928af 100644
--- a/test/mjsunit/es6/regexp-tolength.js
+++ b/test/mjsunit/es6/regexp-tolength.js
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-tolength
-
 'use strict';
 
 let regexp = /x/g;
diff --git a/test/mjsunit/harmony/block-for-sloppy.js b/test/mjsunit/harmony/block-for-sloppy.js
index e9e960504b..051d2b16ea 100644
--- a/test/mjsunit/harmony/block-for-sloppy.js
+++ b/test/mjsunit/harmony/block-for-sloppy.js
@@ -26,7 +26,6 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // Flags: --no-legacy-const --harmony-sloppy --harmony-sloppy-let
-// Flags: --harmony-completion
 
 function props(x) {
   var array = [];
diff --git a/test/mjsunit/harmony/do-expressions.js b/test/mjsunit/harmony/do-expressions.js
index e7e513a230..3aace577d5 100644
--- a/test/mjsunit/harmony/do-expressions.js
+++ b/test/mjsunit/harmony/do-expressions.js
@@ -4,7 +4,6 @@
 
 // Flags: --harmony-do-expressions --harmony-sloppy-let --allow-natives-syntax
 // Flags: --harmony-default-parameters --harmony-destructuring-bind
-// Flags: --harmony-completion
 
 function returnValue(v) { return v; }
 function MyError() {}
diff --git a/test/mjsunit/regress/regress-crbug-516775.js b/test/mjsunit/regress/regress-crbug-516775.js
index 25d4d0103d..df190c149b 100644
--- a/test/mjsunit/regress/regress-crbug-516775.js
+++ b/test/mjsunit/regress/regress-crbug-516775.js
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax --harmony-concat-spreadable
+// Flags: --allow-natives-syntax
 
 function arguments_with_length_getter(f) {
   arguments.__defineGetter__('length', f);