fixed compatibility 
diff --git a/impl/src/main/java/org/apache/myfaces/config/impl/element/LocaleConfigImpl.java b/impl/src/main/java/org/apache/myfaces/config/impl/element/LocaleConfigImpl.java
index 4a203d3..ed1009c 100755
--- a/impl/src/main/java/org/apache/myfaces/config/impl/element/LocaleConfigImpl.java
+++ b/impl/src/main/java/org/apache/myfaces/config/impl/element/LocaleConfigImpl.java
@@ -20,7 +20,6 @@
 
 import java.io.Serializable;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 
 /**
@@ -56,7 +55,7 @@
     {
         if (supportedLocales == null)
         {
-            return Collections.emptyList();
+            supportedLocales = new ArrayList<>();
         }
         return supportedLocales;
     }