diff --git a/layout/style/nsCSSPropAliasList.h b/layout/style/nsCSSPropAliasList.h
index f7938af9e..9ec71b2cf 100644
--- a/layout/style/nsCSSPropAliasList.h
+++ b/layout/style/nsCSSPropAliasList.h
@@ -264,6 +264,11 @@ CSS_PROP_ALIAS(-webkit-animation-timing-function,
                WebkitAnimationTimingFunction,
                WEBKIT_PREFIX_PREF)
 
+CSS_PROP_ALIAS(-webkit-appearance,
+               appearance,
+               WebkitAppearance,
+               WEBKIT_PREFIX_PREF)
+
 CSS_PROP_ALIAS(-webkit-filter,
                filter,
                WebkitFilter,