diff --git a/Meta/gn/secondary/Userland/Libraries/LibWeb/idl_files.gni b/Meta/gn/secondary/Userland/Libraries/LibWeb/idl_files.gni
index ac139ac698..67bf8bd86e 100644
--- a/Meta/gn/secondary/Userland/Libraries/LibWeb/idl_files.gni
+++ b/Meta/gn/secondary/Userland/Libraries/LibWeb/idl_files.gni
@@ -220,6 +220,7 @@ standard_idl_files = get_path_info(
           "//Userland/Libraries/LibWeb/Streams/TransformStream.idl",
           "//Userland/Libraries/LibWeb/Streams/TransformStreamDefaultController.idl",
           "//Userland/Libraries/LibWeb/Streams/WritableStream.idl",
+          "//Userland/Libraries/LibWeb/Streams/WritableStreamDefaultController.idl",
           "//Userland/Libraries/LibWeb/Streams/WritableStreamDefaultWriter.idl",
           "//Userland/Libraries/LibWeb/SVG/SVGAnimatedLength.idl",
           "//Userland/Libraries/LibWeb/SVG/SVGAnimatedNumber.idl",
diff --git a/Userland/Libraries/LibWeb/idl_files.cmake b/Userland/Libraries/LibWeb/idl_files.cmake
index bb85128758..512e30e7c3 100644
--- a/Userland/Libraries/LibWeb/idl_files.cmake
+++ b/Userland/Libraries/LibWeb/idl_files.cmake
@@ -199,6 +199,7 @@ libweb_js_bindings(Streams/ReadableStreamDefaultReader)
 libweb_js_bindings(Streams/TransformStream)
 libweb_js_bindings(Streams/TransformStreamDefaultController)
 libweb_js_bindings(Streams/WritableStream)
+libweb_js_bindings(Streams/WritableStreamDefaultController)
 libweb_js_bindings(Streams/WritableStreamDefaultWriter)
 libweb_js_bindings(SVG/SVGAnimatedLength)
 libweb_js_bindings(SVG/SVGAnimatedNumber)