diff --git a/tests/wpt/webgl/meta/conformance/glsl/variables/gl-pointcoord.html.ini b/tests/wpt/webgl/meta/conformance/glsl/variables/gl-pointcoord.html.ini
index 0bf86fb81c2..aa794bc8d38 100644
--- a/tests/wpt/webgl/meta/conformance/glsl/variables/gl-pointcoord.html.ini
+++ b/tests/wpt/webgl/meta/conformance/glsl/variables/gl-pointcoord.html.ini
@@ -1,4 +1,5 @@
 [gl-pointcoord.html]
+  bug: https://github.com/servo/servo/issues/21719
   [WebGL test #48: pixel 48,192 should be 65,125,0\nat (48, 192) expected: 65,125,0 was 0,0,0]
     expected: FAIL