diff --git a/mozilla/layout/generic/crashtests/421671.html b/mozilla/layout/generic/crashtests/421671.html
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+++ b/mozilla/layout/generic/crashtests/421671.html
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+<marquee>
+<xmp style="-moz-column-count: 99999999">
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+<a>
+<a>
+<a>
+<a>
+																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																						
+<a>
+<a>
+
+<a>
+<a>
\ No newline at end of file
diff --git a/mozilla/layout/generic/crashtests/crashtests.list b/mozilla/layout/generic/crashtests/crashtests.list
index 8a95ee1495c..cb7e6ba947c 100644
--- a/mozilla/layout/generic/crashtests/crashtests.list
+++ b/mozilla/layout/generic/crashtests/crashtests.list
@@ -136,6 +136,7 @@ load 416264-1.html
 load 416476-1.html
 load 418532-1.html
 load 421404-1.html
+load 421671.html
 load 422283-1.html
 load 422301-1.html
 load 425253-1.html