diff --git a/mozilla/layout/forms/resources/skin/select.css b/mozilla/layout/forms/resources/skin/select.css
index 4e82cc4479c..80b9eade36a 100644
--- a/mozilla/layout/forms/resources/skin/select.css
+++ b/mozilla/layout/forms/resources/skin/select.css
@@ -45,7 +45,7 @@
 select[size] {
   border: 2px inset ThreeDFace;
   margin: 0;
-  min-height: none;
+  min-height: 0;
   color: inherit;
 /*  -moz-appearance: treeview; */
 }
diff --git a/mozilla/layout/html/forms/resources/skin/select.css b/mozilla/layout/html/forms/resources/skin/select.css
index 4e82cc4479c..80b9eade36a 100644
--- a/mozilla/layout/html/forms/resources/skin/select.css
+++ b/mozilla/layout/html/forms/resources/skin/select.css
@@ -45,7 +45,7 @@
 select[size] {
   border: 2px inset ThreeDFace;
   margin: 0;
-  min-height: none;
+  min-height: 0;
   color: inherit;
 /*  -moz-appearance: treeview; */
 }