diff --git a/test/built-ins/Object/prototype/toString/symbol-tag-array-builtin.js b/test/built-ins/Object/prototype/toString/symbol-tag-array-builtin.js
new file mode 100644
index 0000000000..3738b94039
--- /dev/null
+++ b/test/built-ins/Object/prototype/toString/symbol-tag-array-builtin.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-object.prototype.tostring
+description: >
+  Non-string values of `Symbol.toStringTag` property are ignored.
+info: |
+  Object.prototype.toString ( )
+
+  [...]
+  15. Let tag be ? Get(O, @@toStringTag).
+  16. If Type(tag) is not String, set tag to builtinTag.
+  17. Return the string-concatenation of "[object ", tag, and "]".
+features: [Symbol.toStringTag, Symbol.iterator]
+---*/
+
+var toString = Object.prototype.toString;
+
+var arrIter = [][Symbol.iterator]();
+var arrIterProto = Object.getPrototypeOf(arrIter);
+
+assert.sameValue(toString.call(arrIter), '[object Array Iterator]');
+
+Object.defineProperty(arrIterProto, Symbol.toStringTag, {configurable: true, value: null});
+assert.sameValue(toString.call(arrIter), '[object Object]');
diff --git a/test/built-ins/Object/prototype/toString/symbol-tag-generators-builtin.js b/test/built-ins/Object/prototype/toString/symbol-tag-generators-builtin.js
new file mode 100644
index 0000000000..06c8350eed
--- /dev/null
+++ b/test/built-ins/Object/prototype/toString/symbol-tag-generators-builtin.js
@@ -0,0 +1,30 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-object.prototype.tostring
+description: >
+  Non-string values of `Symbol.toStringTag` property are ignored.
+info: |
+  Object.prototype.toString ( )
+
+  [...]
+  15. Let tag be ? Get(O, @@toStringTag).
+  16. If Type(tag) is not String, set tag to builtinTag.
+  17. Return the string-concatenation of "[object ", tag, and "]".
+features: [Symbol.toStringTag, Symbol.iterator, generators]
+---*/
+
+var toString = Object.prototype.toString;
+
+var genFn = function* () {};
+assert.sameValue(toString.call(gen), '[object GeneratorFunction]');
+
+var gen = genFn();
+assert.sameValue(toString.call(gen), '[object Generator]');
+
+var genProto = Object.getPrototypeOf(gen);
+Object.defineProperty(genProto, Symbol.toStringTag, {
+  configurable: true,
+  get: function() { return {}; },
+});
+assert.sameValue(toString.call(gen), '[object Object]');
diff --git a/test/built-ins/Object/prototype/toString/symbol-tag-map-builtin.js b/test/built-ins/Object/prototype/toString/symbol-tag-map-builtin.js
new file mode 100644
index 0000000000..dcfbf8bd58
--- /dev/null
+++ b/test/built-ins/Object/prototype/toString/symbol-tag-map-builtin.js
@@ -0,0 +1,30 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-object.prototype.tostring
+description: >
+  Non-string values of `Symbol.toStringTag` property are ignored.
+info: |
+  Object.prototype.toString ( )
+
+  [...]
+  15. Let tag be ? Get(O, @@toStringTag).
+  16. If Type(tag) is not String, set tag to builtinTag.
+  17. Return the string-concatenation of "[object ", tag, and "]".
+features: [Symbol.toStringTag, Symbol.iterator, Map]
+---*/
+
+var toString = Object.prototype.toString;
+
+var map = new Map();
+delete Map.prototype[Symbol.toStringTag];
+assert.sameValue(toString.call(map), '[object Object]');
+
+var mapIter = map[Symbol.iterator]();
+var mapIterProto = Object.getPrototypeOf(mapIter);
+assert.sameValue(toString.call(mapIter), '[object Map Iterator]');
+Object.defineProperty(mapIterProto, Symbol.toStringTag, {
+  configurable: true,
+  get: function() { return new String('ShouldNotBeUnwrapped'); },
+});
+assert.sameValue(toString.call(mapIter), '[object Object]');
diff --git a/test/built-ins/Object/prototype/toString/symbol-tag-non-str-builtin.js b/test/built-ins/Object/prototype/toString/symbol-tag-non-str-builtin.js
index 086b063e85..0a2f40fe6c 100644
--- a/test/built-ins/Object/prototype/toString/symbol-tag-non-str-builtin.js
+++ b/test/built-ins/Object/prototype/toString/symbol-tag-non-str-builtin.js
@@ -11,7 +11,7 @@ info: |
   15. Let tag be ? Get(O, @@toStringTag).
   16. If Type(tag) is not String, set tag to builtinTag.
   17. Return the string-concatenation of "[object ", tag, and "]".
-features: [Symbol.toStringTag, Symbol.iterator, generators, WeakMap, iterator-helpers]
+features: [Symbol.toStringTag]
 ---*/
 
 var toString = Object.prototype.toString;
@@ -22,58 +22,6 @@ assert.sameValue(toString.call(Symbol('desc')), '[object Object]');
 Object.defineProperty(Math, Symbol.toStringTag, {value: Symbol()});
 assert.sameValue(toString.call(Math), '[object Object]');
 
-var strIter = ''[Symbol.iterator]();
-var strIterProto = Object.getPrototypeOf(strIter);
-assert.sameValue(toString.call(strIter), '[object String Iterator]');
-delete strIterProto[Symbol.toStringTag];
-assert.sameValue(toString.call(strIter), '[object Iterator]');
-
-var arrIter = [][Symbol.iterator]();
-var arrIterProto = Object.getPrototypeOf(arrIter)
-assert.sameValue(toString.call(arrIter), '[object Array Iterator]');
-Object.defineProperty(arrIterProto, Symbol.toStringTag, {value: null});
-assert.sameValue(toString.call(arrIter), '[object Object]');
-
-var map = new Map();
-delete Map.prototype[Symbol.toStringTag];
-assert.sameValue(toString.call(map), '[object Object]');
-
-var mapIter = map[Symbol.iterator]();
-var mapIterProto = Object.getPrototypeOf(mapIter);
-assert.sameValue(toString.call(mapIter), '[object Map Iterator]');
-Object.defineProperty(mapIterProto, Symbol.toStringTag, {
-  get: function() { return new String('ShouldNotBeUnwrapped'); },
-});
-assert.sameValue(toString.call(mapIter), '[object Object]');
-
-var set = new Set();
-delete Set.prototype[Symbol.toStringTag];
-assert.sameValue(toString.call(set), '[object Object]');
-
-var setIter = set[Symbol.iterator]();
-var setIterProto = Object.getPrototypeOf(setIter);
-assert.sameValue(toString.call(setIter), '[object Set Iterator]');
-Object.defineProperty(setIterProto, Symbol.toStringTag, {value: false});
-assert.sameValue(toString.call(setIter), '[object Object]');
-
-var wm = new WeakMap();
-delete WeakMap.prototype[Symbol.toStringTag];
-assert.sameValue(toString.call(wm), '[object Object]');
-
-var ws = new WeakSet();
-Object.defineProperty(WeakSet.prototype, Symbol.toStringTag, {value: 0});
-assert.sameValue(toString.call(ws), '[object Object]');
-
 delete JSON[Symbol.toStringTag];
 assert.sameValue(toString.call(JSON), '[object Object]');
 
-var gen = (function* () {})();
-var genProto = Object.getPrototypeOf(gen);
-Object.defineProperty(genProto, Symbol.toStringTag, {
-  get: function() { return {}; },
-});
-assert.sameValue(toString.call(gen), '[object Object]');
-
-var promise = new Promise(function() {});
-delete Promise.prototype[Symbol.toStringTag];
-assert.sameValue(toString.call(promise), '[object Object]');
diff --git a/test/built-ins/Object/prototype/toString/symbol-tag-promise-builtin.js b/test/built-ins/Object/prototype/toString/symbol-tag-promise-builtin.js
new file mode 100644
index 0000000000..cd527ff935
--- /dev/null
+++ b/test/built-ins/Object/prototype/toString/symbol-tag-promise-builtin.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-object.prototype.tostring
+description: >
+  Non-string values of `Symbol.toStringTag` property are ignored.
+info: |
+  Object.prototype.toString ( )
+
+  [...]
+  15. Let tag be ? Get(O, @@toStringTag).
+  16. If Type(tag) is not String, set tag to builtinTag.
+  17. Return the string-concatenation of "[object ", tag, and "]".
+features: [Symbol.toStringTag, Promise]
+---*/
+
+var toString = Object.prototype.toString;
+
+var promise = new Promise(function () {});
+assert.sameValue(toString.call(promise), '[object Promise]');
diff --git a/test/built-ins/Object/prototype/toString/symbol-tag-set-builtin.js b/test/built-ins/Object/prototype/toString/symbol-tag-set-builtin.js
new file mode 100644
index 0000000000..7813a7331e
--- /dev/null
+++ b/test/built-ins/Object/prototype/toString/symbol-tag-set-builtin.js
@@ -0,0 +1,30 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-object.prototype.tostring
+description: >
+  Non-string values of `Symbol.toStringTag` property are ignored.
+info: |
+  Object.prototype.toString ( )
+
+  [...]
+  15. Let tag be ? Get(O, @@toStringTag).
+  16. If Type(tag) is not String, set tag to builtinTag.
+  17. Return the string-concatenation of "[object ", tag, and "]".
+features: [Symbol.toStringTag, Symbol.iterator, Set]
+---*/
+
+var toString = Object.prototype.toString;
+
+var set = new Set();
+delete Set.prototype[Symbol.toStringTag];
+assert.sameValue(toString.call(set), '[object Object]');
+
+var setIter = set[Symbol.iterator]();
+var setIterProto = Object.getPrototypeOf(setIter);
+assert.sameValue(toString.call(setIter), '[object Set Iterator]');
+Object.defineProperty(setIterProto, Symbol.toStringTag, {
+  configurable: true,
+  get: function() { return new String('ShouldNotBeUnwrapped'); },
+});
+assert.sameValue(toString.call(setIter), '[object Object]');
diff --git a/test/built-ins/Object/prototype/toString/symbol-tag-string-builtin.js b/test/built-ins/Object/prototype/toString/symbol-tag-string-builtin.js
new file mode 100644
index 0000000000..9ed71ecc48
--- /dev/null
+++ b/test/built-ins/Object/prototype/toString/symbol-tag-string-builtin.js
@@ -0,0 +1,28 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-object.prototype.tostring
+description: >
+  Non-string values of `Symbol.toStringTag` property are ignored.
+info: |
+  Object.prototype.toString ( )
+
+  [...]
+  15. Let tag be ? Get(O, @@toStringTag).
+  16. If Type(tag) is not String, set tag to builtinTag.
+  17. Return the string-concatenation of "[object ", tag, and "]".
+features: [Symbol.toStringTag, Symbol.iterator]
+---*/
+
+var toString = Object.prototype.toString;
+
+var strIter = ''[Symbol.iterator]();
+var strIterProto = Object.getPrototypeOf(strIter);
+
+assert.sameValue(toString.call(strIter), '[object String Iterator]');
+
+Object.defineProperty(strIterProto, Symbol.toStringTag, {
+  configurable: true,
+  get: function() { return new String('ShouldNotBeUnwrapped'); },
+});
+assert.sameValue(toString.call(strIter), '[object Object]');
diff --git a/test/built-ins/Object/prototype/toString/symbol-tag-weakmap-builtin.js b/test/built-ins/Object/prototype/toString/symbol-tag-weakmap-builtin.js
new file mode 100644
index 0000000000..46980cda4d
--- /dev/null
+++ b/test/built-ins/Object/prototype/toString/symbol-tag-weakmap-builtin.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-object.prototype.tostring
+description: >
+  Non-string values of `Symbol.toStringTag` property are ignored.
+info: |
+  Object.prototype.toString ( )
+
+  [...]
+  15. Let tag be ? Get(O, @@toStringTag).
+  16. If Type(tag) is not String, set tag to builtinTag.
+  17. Return the string-concatenation of "[object ", tag, and "]".
+features: [Symbol.toStringTag, WeakMap]
+---*/
+
+var toString = Object.prototype.toString;
+
+var wm = new WeakMap();
+delete WeakMap.prototype[Symbol.toStringTag];
+assert.sameValue(toString.call(wm), '[object Object]');
\ No newline at end of file
diff --git a/test/built-ins/Object/prototype/toString/symbol-tag-weakset-builtin.js b/test/built-ins/Object/prototype/toString/symbol-tag-weakset-builtin.js
new file mode 100644
index 0000000000..764f4b7ee3
--- /dev/null
+++ b/test/built-ins/Object/prototype/toString/symbol-tag-weakset-builtin.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-object.prototype.tostring
+description: >
+  Non-string values of `Symbol.toStringTag` property are ignored.
+info: |
+  Object.prototype.toString ( )
+
+  [...]
+  15. Let tag be ? Get(O, @@toStringTag).
+  16. If Type(tag) is not String, set tag to builtinTag.
+  17. Return the string-concatenation of "[object ", tag, and "]".
+features: [Symbol.toStringTag, WeakSet]
+---*/
+
+var toString = Object.prototype.toString;
+
+var wm = new WeakSet();
+delete WeakSet.prototype[Symbol.toStringTag];
+assert.sameValue(toString.call(wm), '[object Object]');
\ No newline at end of file