diff --git a/layout/reftests/bugs/reftest.list b/layout/reftests/bugs/reftest.list
index 87e1dbb728d7..60be5c9bde19 100644
--- a/layout/reftests/bugs/reftest.list
+++ b/layout/reftests/bugs/reftest.list
@@ -1229,7 +1229,7 @@ skip-if(B2G) == 458296-1d.html 458296-1-ref.html
 skip-if(B2G&&browserIsRemote) == 463217-1.xul 463217-1-ref.xul # bug 974780
 skip-if(B2G) == 463952-1.html 463952-1-ref.html
 == 464811-1.html 464811-1-ref.html
-== 465574-1.html 465574-1-ref.html
+fails == 465574-1.html 465574-1-ref.html # bug 421436
 == 466258-1.html 466258-1-ref.html
 == 466395-1.html 466395-1-ref.html
 == 466395-2.html 466395-2-ref.html