--- a/jdk/src/share/classes/sun/security/ssl/SignatureAndHashAlgorithm.java	Wed Dec 18 10:43:11 2013 +0400
+++ b/jdk/src/share/classes/sun/security/ssl/SignatureAndHashAlgorithm.java	Fri Jan 10 13:42:44 2014 -0800
@@ -68,7 +68,7 @@
 
     // performance optimization
     private final static Set<CryptoPrimitive> SIGNATURE_PRIMITIVE_SET =
-                                    EnumSet.of(CryptoPrimitive.SIGNATURE);
+        Collections.unmodifiableSet(EnumSet.of(CryptoPrimitive.SIGNATURE));
 
     // supported pairs of signature and hash algorithm
     private final static Map<Integer, SignatureAndHashAlgorithm> supportedMap;