--- a/js/src/devtools/automation/cgc-jstests-slow.txt
+++ b/js/src/devtools/automation/cgc-jstests-slow.txt
@@ -58,20 +58,20 @@ non262/regress/regress-360969-02.js
 non262/regress/regress-360969-03.js
 non262/regress/regress-360969-04.js
 non262/regress/regress-360969-05.js
 non262/regress/regress-360969-06.js
 non262/extensions/regress-477187.js
 non262/regress/regress-452498-052-a.js
 non262/extensions/clone-complex-object.js
 non262/extensions/clone-object-deep.js
-test262/built-ins/RegExp/CharacterClassEscapes/character-class-word-class-escape-flags-u.js
+test262/built-ins/RegExp/CharacterClassEscapes/character-class-digit-class-escape-flags-u.js
+test262/built-ins/RegExp/CharacterClassEscapes/character-class-digit-class-escape-plus-quantifier-flags-u.js
+test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-digit-class-escape-flags-u.js
 test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-digit-class-escape-plus-quantifier-flags-u.js
-test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-digit-class-escape-flags-u.js
-test262/built-ins/RegExp/CharacterClassEscapes/character-class-whitespace-class-escape-flags-u.js
+test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-whitespace-class-escape-flags-u.js
 test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-whitespace-class-escape-plus-quantifier-flags-u.js
-test262/built-ins/RegExp/CharacterClassEscapes/character-class-digit-class-escape-flags-u.js
+test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-word-class-escape-flags-u.js
 test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-word-class-escape-plus-quantifier-flags-u.js
-test262/built-ins/RegExp/CharacterClassEscapes/character-class-digit-class-escape-plus-quantifier-flags-u.js
+test262/built-ins/RegExp/CharacterClassEscapes/character-class-whitespace-class-escape-flags-u.js
+test262/built-ins/RegExp/CharacterClassEscapes/character-class-whitespace-class-escape-plus-quantifier-flags-u.js
+test262/built-ins/RegExp/CharacterClassEscapes/character-class-word-class-escape-flags-u.js
 test262/built-ins/RegExp/CharacterClassEscapes/character-class-word-class-escape-plus-quantifier-flags-u.js
-test262/built-ins/RegExp/CharacterClassEscapes/character-class-whitespace-class-escape-plus-quantifier-flags-u.js
-test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-whitespace-class-escape-flags-u.js
-test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-word-class-escape-flags-u.js

--- a/js/src/tests/jstests.list
+++ b/js/src/tests/jstests.list
@@ -1,19 +1,31 @@
 # Manifest entries for imported test suites whose individual test cases
 # we don't want to change.
 
 # Skip the folder with tests for the scripts
 skip include test/jstests.list
 
 skip script non262/String/normalize-generateddata-input.js # input data for other test
 
-# Times out on arm and cgc builds.
+# Timeouts on arm and cgc builds.
 slow script test262/built-ins/decodeURI/S15.1.3.1_A2.5_T1.js
 slow script test262/built-ins/decodeURIComponent/S15.1.3.2_A2.5_T1.js
+slow script test262/built-ins/RegExp/CharacterClassEscapes/character-class-digit-class-escape-flags-u.js
+slow script test262/built-ins/RegExp/CharacterClassEscapes/character-class-digit-class-escape-plus-quantifier-flags-u.js
+slow script test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-digit-class-escape-flags-u.js
+slow script test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-digit-class-escape-plus-quantifier-flags-u.js
+slow script test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-whitespace-class-escape-flags-u.js
+slow script test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-whitespace-class-escape-plus-quantifier-flags-u.js
+slow script test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-word-class-escape-flags-u.js
+slow script test262/built-ins/RegExp/CharacterClassEscapes/character-class-non-word-class-escape-plus-quantifier-flags-u.js
+slow script test262/built-ins/RegExp/CharacterClassEscapes/character-class-whitespace-class-escape-flags-u.js
+slow script test262/built-ins/RegExp/CharacterClassEscapes/character-class-whitespace-class-escape-plus-quantifier-flags-u.js
+slow script test262/built-ins/RegExp/CharacterClassEscapes/character-class-word-class-escape-flags-u.js
+slow script test262/built-ins/RegExp/CharacterClassEscapes/character-class-word-class-escape-plus-quantifier-flags-u.js
 
 
 #################################################################
 # Tests disabled due to intentional alternative implementations #
 #################################################################
 
 # Legacy "caller" and "arguments" implemented as accessor properties on Function.prototype.
 skip script test262/built-ins/Function/prototype/restricted-property-arguments.js