--- old/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/HeapHprofBinWriter.java	2018-11-21 22:00:13.876000000 +0530
+++ new/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/HeapHprofBinWriter.java	2018-11-21 22:00:13.580000000 +0530
@@ -32,6 +32,7 @@
 import sun.jvm.hotspot.oops.*;
 import sun.jvm.hotspot.runtime.*;
 import sun.jvm.hotspot.classfile.*;
+import sun.jvm.hotspot.gc.z.ZCollectedHeap;
 
 /*
  * This class writes Java heap in hprof binary format. This format is
@@ -393,6 +394,10 @@
         out = new DataOutputStream(new BufferedOutputStream(fos));
 
         VM vm = VM.getVM();
+        if (vm.getUniverse().heap() instanceof ZCollectedHeap) {
+            throw new RuntimeException("This operation is not supported with ZGC.");
+        }
+
         dbg = vm.getDebugger();
         objectHeap = vm.getObjectHeap();