--- old/src/macosx/native/sun/awt/AWTWindow.m	2012-06-28 19:15:00.381843033 +0400
+++ new/src/macosx/native/sun/awt/AWTWindow.m	2012-06-28 19:15:00.205843029 +0400
@@ -941,14 +941,17 @@
 (JNIEnv *env, jclass clazz, jlong windowPtr)
 {
 JNF_COCOA_ENTER(env);
-AWT_ASSERT_NOT_APPKIT_THREAD;
 
     NSWindow *nsWindow = OBJC(windowPtr);
-    [JNFRunLoop performOnMainThreadWaiting:NO withBlock:^(){
-        AWT_ASSERT_APPKIT_THREAD;
-
+    if ([NSThread isMainThread]) {
         [nsWindow invalidateShadow];
-    }];
+    } else {
+        [JNFRunLoop performOnMainThreadWaiting:NO withBlock:^(){
+            AWT_ASSERT_APPKIT_THREAD;
+
+            [nsWindow invalidateShadow];
+        }];
+    }
 
 JNF_COCOA_EXIT(env);
 }