--- a/langtools/src/share/classes/com/sun/tools/javac/code/Source.java	Mon Dec 10 12:10:50 2012 +0000
+++ b/langtools/src/share/classes/com/sun/tools/javac/code/Source.java	Mon Dec 10 16:21:26 2012 +0000
@@ -87,7 +87,7 @@
 
     public final String name;
 
-    private static Map<String,Source> tab = new HashMap<String,Source>();
+    private static final Map<String,Source> tab = new HashMap<String,Source>();
     static {
         for (Source s : values()) {
             tab.put(s.name, s);