diff --git a/layout/reftests/bugs/391979-ref.html b/layout/reftests/bugs/391979-ref.html
index b6f35f181424..80c6c911da0e 100644
--- a/layout/reftests/bugs/391979-ref.html
+++ b/layout/reftests/bugs/391979-ref.html
@@ -8,7 +8,7 @@
color:black; background-color:white; font-size:16px; padding:0; margin:0;
}
- div { background:green; width:70ch; height:2ch; }
+ div { background:green; width:20ch; height:2ch; }
diff --git a/layout/reftests/bugs/391979.html b/layout/reftests/bugs/391979.html
index c6d1ea1b30ed..09e660d92036 100644
--- a/layout/reftests/bugs/391979.html
+++ b/layout/reftests/bugs/391979.html
@@ -9,9 +9,9 @@
}
.float { float:left; clear:both; }
- .t1 { -moz-column-count:2; -moz-column-width: 30ch; -moz-column-gap: 10ch; background:red; height:2ch; }
+ .t1 { -moz-column-count:2; -moz-column-width: 9ch; -moz-column-gap: 2ch; background:red; height:2ch; }
- .abs { position:absolute; width:70ch; height:2ch; }
+ .abs { position:absolute; width:20ch; height:2ch; }
.red { background:red; }
.green { background:green; }
diff --git a/layout/reftests/bugs/reftest.list b/layout/reftests/bugs/reftest.list
index 8606ec3930c9..34cd02034138 100644
--- a/layout/reftests/bugs/reftest.list
+++ b/layout/reftests/bugs/reftest.list
@@ -516,7 +516,7 @@ skip-if(MOZ_WIDGET_TOOLKIT!="windows") == 391045.html 391045-ref.html # windows-
== 391412-1a.html 391412-1-ref.html
== 391412-1b.html 391412-1-ref.html
== 391909-1.html 391909-1-ref.html
-# == 391979.html 391979-ref.html
+== 391979.html 391979-ref.html
== 391994-1.html 391994-1-ref.html
== 392435-1.html 392435-1-ref.html
== 393330-1.html 393330-1-ref.html