diff --git a/lib/web_ui/lib/src/ui/window.dart b/lib/web_ui/lib/src/ui/window.dart
index bf3183786384cdad0f0b3a529715df0db883baee..8f7febcc75aa0ac581e881090b47d586c17b8edc 100644
--- a/lib/web_ui/lib/src/ui/window.dart
+++ b/lib/web_ui/lib/src/ui/window.dart
@@ -1118,7 +1118,7 @@ class PluginUtilities {
 }
 
 // TODO(flutter_web): see https://github.com/flutter/flutter/issues/33616.
-class ImageShader {
+class ImageShader implements Shader {
   ImageShader(Image image, TileMode tmx, TileMode tmy, Float64List matrix4);
 }