diff -r 4722e25bfd6d -r 14f7f48c1377 hotspot/agent/src/share/classes/sun/jvm/hotspot/code/CodeBlob.java
--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/code/CodeBlob.java	Fri Apr 24 10:49:38 2015 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/code/CodeBlob.java	Tue May 05 16:50:25 2015 +0200
@@ -171,17 +171,17 @@
   public boolean isLockedByVM()         { return false; }
 
   /** OopMap for frame; can return null if none available */
-  public OopMapSet getOopMaps() {
+  public ImmutableOopMapSet getOopMaps() {
     Address oopMapsAddr = oopMapsField.getValue(addr);
     if (oopMapsAddr == null) {
       return null;
     }
-    return new OopMapSet(oopMapsAddr);
+    return new ImmutableOopMapSet(oopMapsAddr);
   }
   // FIXME: not yet implementable
-  //  void set_oop_maps(OopMapSet* p);
+  //  void set_oop_maps(ImmutableOopMapSet* p);
 
-  public OopMap getOopMapForReturnAddress(Address returnAddress, boolean debugging) {
+  public ImmutableOopMap getOopMapForReturnAddress(Address returnAddress, boolean debugging) {
     Address pc = returnAddress;
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(getOopMaps() != null, "nope");