--- a/src/java.desktop/macosx/native/libawt_lwawt/awt/AWTWindow.m	Fri Jan 04 11:40:53 2019 +0530
+++ b/src/java.desktop/macosx/native/libawt_lwawt/awt/AWTWindow.m	Sat Jan 05 10:13:58 2019 -0800
@@ -471,7 +471,7 @@
 
     JNIEnv *env = [ThreadUtilities getJNIEnvUncached];
     [self.javaPlatformWindow setJObject:nil withEnv:env];
-
+    self.javaPlatformWindow = nil;
     self.nsWindow = nil;
     self.ownerWindow = nil;
     [super dealloc];