diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index 956a3e5..ded446b 100644
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,5 +1,24 @@
 2022-01-25  Alexey Shvayka  <ashvayka@apple.com>
 
+        [WebIDL] Remove the now-unused [CustomEnabled] extended attribute
+        https://bugs.webkit.org/show_bug.cgi?id=235608
+
+        Reviewed by Darin Adler.
+
+        It's unlikely we will ever need it, and it's limited to Window only,
+        and it generates a call to a free function rather than a method.
+
+        No new tests, no behavior change.
+
+        * bindings/scripts/CodeGeneratorJS.pm:
+        (NeedsRuntimeCheck):
+        (GenerateRuntimeEnableConditionalString):
+        * bindings/scripts/IDLAttributes.json:
+        * bindings/scripts/preprocess-idls.pl:
+        (GenerateConstructorAttributes):
+
+2022-01-25  Alexey Shvayka  <ashvayka@apple.com>
+
         [WebIDL] Blob-related methods should use _relevant_ context instead of _current_
         https://bugs.webkit.org/show_bug.cgi?id=235279
 
diff --git a/Source/WebCore/bindings/scripts/CodeGeneratorJS.pm b/Source/WebCore/bindings/scripts/CodeGeneratorJS.pm
index 7920c9b..873181d 100644
--- a/Source/WebCore/bindings/scripts/CodeGeneratorJS.pm
+++ b/Source/WebCore/bindings/scripts/CodeGeneratorJS.pm
@@ -1994,8 +1994,7 @@
         || $context->extendedAttributes->{EnabledBySetting}
         || $context->extendedAttributes->{EnabledByQuirk}
         || $context->extendedAttributes->{DisabledByQuirk}
-        || $context->extendedAttributes->{SecureContext}
-        || $context->extendedAttributes->{CustomEnabled};
+        || $context->extendedAttributes->{SecureContext};
 }
 
 sub NeedsRuntimeReadWriteCheck
@@ -4046,13 +4045,6 @@
         }
     }
 
-    if ($context->extendedAttributes->{CustomEnabled}) {
-        assert("CustomEnabled can only be used by interfaces only exposed to the Window") if $interface->extendedAttributes->{Exposed} && $interface->extendedAttributes->{Exposed} ne "Window";
-
-        my $className = "JS" . $interface->type->name;
-        push(@conjuncts, "${className}" . $codeGenerator->WK_ucfirst($context->name) . "IsEnabled()");
-    }
-
     if ($context->extendedAttributes->{EnabledByQuirk}) {
         assert("Must specify value for EnabledByQuirk.") if $context->extendedAttributes->{DisabledByQuirk} eq "VALUE_IS_MISSING";
 
diff --git a/Source/WebCore/bindings/scripts/IDLAttributes.json b/Source/WebCore/bindings/scripts/IDLAttributes.json
index ba5c0db..78dfdf1 100644
--- a/Source/WebCore/bindings/scripts/IDLAttributes.json
+++ b/Source/WebCore/bindings/scripts/IDLAttributes.json
@@ -144,9 +144,6 @@
         "CustomToJSObject": {
             "contextsAllowed": ["interface"]
         },
-        "CustomEnabled": {
-            "contextsAllowed": ["interface", "dictionary", "enum", "attribute", "operation", "constant", "iterable"]
-        },
         "DOMJIT": {
             "contextsAllowed": ["interface", "attribute", "operation"],
             "values": ["", "ReadDOM", "Getter"],
diff --git a/Source/WebCore/bindings/scripts/preprocess-idls.pl b/Source/WebCore/bindings/scripts/preprocess-idls.pl
index 741a58b..e2f1e35 100644
--- a/Source/WebCore/bindings/scripts/preprocess-idls.pl
+++ b/Source/WebCore/bindings/scripts/preprocess-idls.pl
@@ -480,7 +480,7 @@
       next unless ($attributeName eq "Conditional" || $attributeName eq "EnabledAtRuntime" || $attributeName eq "EnabledForWorld"
         || $attributeName eq "EnabledBySetting" || $attributeName eq "SecureContext" || $attributeName eq "PrivateIdentifier"
         || $attributeName eq "PublicIdentifier" || $attributeName eq "DisabledByQuirk" || $attributeName eq "EnabledByQuirk"
-        || $attributeName eq "EnabledForContext" || $attributeName eq "CustomEnabled") || $attributeName eq "LegacyFactoryFunctionEnabledBySetting";
+        || $attributeName eq "EnabledForContext") || $attributeName eq "LegacyFactoryFunctionEnabledBySetting";
       my $extendedAttribute = $attributeName;
       
       $extendedAttribute .= "=" . $extendedAttributes->{$attributeName} unless $extendedAttributes->{$attributeName} eq "VALUE_IS_MISSING";