diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-1.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-1.js
index d0445fd3ab..08925e079b 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-1.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-1.js
@@ -5,7 +5,6 @@
 info: Mapped arguments object with non-configurable property
 description: >
     Mapped value is not changed when property was made non-configurable.
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-2.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-2.js
index 9bd0acd884..265481e015 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-2.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-2.js
@@ -6,7 +6,6 @@ info: Mapped arguments object with non-configurable property
 description: >
     Mapping works when property is non-configurable, variable is
     changed with SetMutableBinding.
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-3.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-3.js
index 7db25bffa7..6877a0c9d9 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-3.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-3.js
@@ -6,7 +6,6 @@ info: Mapped arguments object with non-configurable property
 description: >
     Mapping works when property is non-configurable, arguments property
     is changed with [[DefineOwnProperty]].
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-4.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-4.js
index 4aebeced23..d2ac4d376c 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-4.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-4.js
@@ -6,7 +6,6 @@ info: Mapped arguments object with non-configurable property
 description: >
     Mapping works when property is non-configurable, arguments property
     is changed with [[Set]].
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-1.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-1.js
index b30b22a020..67f9713691 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-1.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-1.js
@@ -6,7 +6,6 @@ info: Mapped arguments object with non-configurable property
 description: >
     Mapping works when property is non-configurable, arguments property
     was not deleted. [[Delete]] operation returns false.
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-2.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-2.js
index bb4bde6136..9a089eaacc 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-2.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-2.js
@@ -6,7 +6,6 @@ info: Mapped arguments object with non-configurable property
 description: >
     Mapping works when property is non-configurable, arguments property
     was not deleted. Variable is changed with SetMutableBinding.
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-3.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-3.js
index 40bc07c71f..26676a4eee 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-3.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-3.js
@@ -7,7 +7,6 @@ description: >
     Mapping works when property is non-configurable, arguments property
     was not deleted. Arguments property is changed with
     [[DefineOwnProperty]].
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-4.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-4.js
index 2cd5a04d45..ed96a0e67a 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-4.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-delete-4.js
@@ -7,7 +7,6 @@ description: >
     Mapping works when property is non-configurable, arguments property
     was not deleted. Arguments property is changed with
     [[Set]].
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-1.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-1.js
index 8f6b0b3454..cfeba05c48 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-1.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-1.js
@@ -8,7 +8,6 @@ description: >
     non-writable. Perform property attribute changes with a single
     [[DefineOwnProperty]] call. Mapped values are unchanged, mapping
     itself is removed.
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-2.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-2.js
index 62d1016f28..69c0e125ba 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-2.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-2.js
@@ -8,7 +8,6 @@ description: >
     non-writable. Perform property attribute changes with two
     consecutive [[DefineOwnProperty]] calls. Mapped values are
     unchanged, mapping itself is removed.
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-3.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-3.js
index e0588955c8..aac554c2f3 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-3.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-3.js
@@ -8,7 +8,7 @@ description: >
     non-writable. Perform property attribute changes with two
     [[DefineOwnProperty]] calls. Add intervening call to
     SetMutableBinding.
-includes: [assert.js]
+    Specification bug: https://bugs.ecmascript.org/show_bug.cgi?id=4371
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-4.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-4.js
index ced92a2608..80d56fe1c5 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-4.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-4.js
@@ -7,7 +7,6 @@ description: >
     Mapped arguments property is changed to non-configurable and
     non-writable. Perform property attribute changes with two
     [[DefineOwnProperty]] calls. Add intervening call to [[Set]].
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-5.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-5.js
index 35f4410aa5..bbb951502d 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-5.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-nonwritable-5.js
@@ -8,7 +8,6 @@ description: >
     non-writable. Perform property attribute changes with two
     [[DefineOwnProperty]] calls. Add intervening call to
     [[DefineOwnProperty]].
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-1.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-1.js
index 2986447e85..b918f75a10 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-1.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-1.js
@@ -7,7 +7,6 @@ description: >
     Mapping works when property is non-configurable, arguments property
     was not deleted. [[Delete]] operations throws TypeError if called
     from strict-mode code.
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-2.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-2.js
index 817fd2b3e3..01afbe4de3 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-2.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-2.js
@@ -7,7 +7,6 @@ description: >
     Mapping works when property is non-configurable, arguments property
     was not deleted. [[Delete]] operations throws TypeError if called
     from strict-mode code. Variable is changed with SetMutableBinding.
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-3.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-3.js
index ff43bd6f47..9aa2a2ed23 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-3.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-3.js
@@ -8,7 +8,6 @@ description: >
     was not deleted. [[Delete]] operations throws TypeError if called
     from strict-mode code. Arguments property is changed with
     [[DefineOwnProperty]].
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-4.js b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-4.js
index c84cf778f5..b480188436 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-4.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonconfigurable-strict-delete-4.js
@@ -7,7 +7,6 @@ description: >
     Mapping works when property is non-configurable, arguments property
     was not deleted. [[Delete]] operations throws TypeError if called
     from strict-mode code. Arguments property is changed with [[Set]].
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-1.js b/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-1.js
index d70d70a399..2dae076788 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-1.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-1.js
@@ -8,7 +8,6 @@ description: >
     non-configurable. Perform property attribute changes with two
     consecutive [[DefineOwnProperty]] calls. Mapped values are
     unchanged, mapping itself is removed.
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-2.js b/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-2.js
index b41384d05c..63585b437e 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-2.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-2.js
@@ -8,7 +8,6 @@ description: >
     non-configurable. Perform property attribute changes with two
     [[DefineOwnProperty]] calls. Add intervening call to
     SetMutableBinding.
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-3.js b/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-3.js
index bf601d404e..2bd1bc9c12 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-3.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-3.js
@@ -7,7 +7,6 @@ description: >
     Mapped arguments property is changed to non-writable and
     non-configurable. Perform property attribute changes with two
     [[DefineOwnProperty]] calls. Add intervening call to [[Set]].
-includes: [assert.js]
 flags: [noStrict]
 ---*/
 
diff --git a/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-4.js b/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-4.js
index 62f11cb2d6..ea40a49a82 100755
--- a/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-4.js
+++ b/test/language/arguments-object/mapped/mapped-arguments-nonwritable-nonconfigurable-4.js
@@ -8,7 +8,6 @@ description: >
     non-configurable. Perform property attribute changes with two
     [[DefineOwnProperty]] calls. Add intervening call to
     [[DefineOwnProperty]].
-includes: [assert.js]
 flags: [noStrict]
 ---*/