diff --git a/mozilla/content/shared/src/nsCSSProps.cpp b/mozilla/content/shared/src/nsCSSProps.cpp
index 27965d9d23a..e70c86bc60f 100644
--- a/mozilla/content/shared/src/nsCSSProps.cpp
+++ b/mozilla/content/shared/src/nsCSSProps.cpp
@@ -895,7 +895,10 @@ static const PRInt32 kBackgroundYPositionKTable[] = {
 
   case eCSSProperty__moz_border_radius:
     break;
-  
+
+  case eCSSProperty_appearance:
+    return SearchKeywordTable(aValue, kAppearanceKTable);
+
   case eCSSProperty_azimuth:
     return SearchKeywordTable(aValue, kAzimuthKTable);
 
diff --git a/mozilla/layout/style/nsCSSProps.cpp b/mozilla/layout/style/nsCSSProps.cpp
index 27965d9d23a..e70c86bc60f 100644
--- a/mozilla/layout/style/nsCSSProps.cpp
+++ b/mozilla/layout/style/nsCSSProps.cpp
@@ -895,7 +895,10 @@ static const PRInt32 kBackgroundYPositionKTable[] = {
 
   case eCSSProperty__moz_border_radius:
     break;
-  
+
+  case eCSSProperty_appearance:
+    return SearchKeywordTable(aValue, kAppearanceKTable);
+
   case eCSSProperty_azimuth:
     return SearchKeywordTable(aValue, kAzimuthKTable);