--- old/src/share/vm/prims/unsafe.cpp	2016-10-25 10:40:09.140777503 +0200
+++ new/src/share/vm/prims/unsafe.cpp	2016-10-25 10:40:09.093777472 +0200
@@ -1289,9 +1289,12 @@
 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread))
   UnsafeWrapper("Unsafe_Unpark");
   Parker* p = NULL;
+  oop java_thread = NULL;
+  JavaThread* thr = NULL;
   if (jthread != NULL) {
-    oop java_thread = JNIHandles::resolve_non_null(jthread);
+    java_thread = JNIHandles::resolve_non_null(jthread);
     if (java_thread != NULL) {
+      thr = java_lang_Thread::thread(java_thread);
       jlong lp = java_lang_Thread::park_event(java_thread);
       if (lp != 0) {
         // This cast is OK even though the jlong might have been read
@@ -1303,7 +1306,7 @@
         MutexLocker mu(Threads_lock);
         java_thread = JNIHandles::resolve_non_null(jthread);
         if (java_thread != NULL) {
-          JavaThread* thr = java_lang_Thread::thread(java_thread);
+          thr = java_lang_Thread::thread(java_thread);
           if (thr != NULL) {
             p = thr->parker();
             if (p != NULL) { // Bind to Java thread for next time.
@@ -1314,14 +1317,14 @@
       }
     }
   }
-  if (p != NULL) {
+  if (p != NULL && thr != NULL) {
 #ifndef USDT2
     HS_DTRACE_PROBE1(hotspot, thread__unpark, p);
 #else /* USDT2 */
     HOTSPOT_THREAD_UNPARK(
                           (uintptr_t) p);
 #endif /* USDT2 */
-    p->unpark();
+    p->unpark(thr);
   }
 UNSAFE_END