diff --git a/tests/wpt/webgl/meta/conformance/canvas/drawingbuffer-test.html.ini b/tests/wpt/webgl/meta/conformance/canvas/drawingbuffer-test.html.ini
index a03aad6f02d..1fe2084d611 100644
--- a/tests/wpt/webgl/meta/conformance/canvas/drawingbuffer-test.html.ini
+++ b/tests/wpt/webgl/meta/conformance/canvas/drawingbuffer-test.html.ini
@@ -1,2 +1,3 @@
 [drawingbuffer-test.html]
+  bug: https://github.com/servo/servo/issues/21718
   expected: CRASH