diff --git a/layout/style/nsCSSDeclaration.cpp b/layout/style/nsCSSDeclaration.cpp
index acb39dd414f..7ae5facafdd 100644
--- a/layout/style/nsCSSDeclaration.cpp
+++ b/layout/style/nsCSSDeclaration.cpp
@@ -371,9 +371,6 @@ nsCSSDeclaration::AppendCSSValueToString(nsCSSProperty aProperty,
                                            aResult);
       }
     }
-    else if (eCSSProperty_transition_property == aProperty) {
-      AppendASCIItoUTF16(nsCSSProps::GetStringValue((nsCSSProperty) aValue.GetIntValue()), aResult);
-    }
     else {
       const nsAFlatCString& name = nsCSSProps::LookupPropertyValue(aProperty, aValue.GetIntValue());
       AppendASCIItoUTF16(name, aResult);