--- old/test/hotspot/jtreg/gc/logging/TestUnifiedLoggingSwitchStress.java	2018-06-01 23:13:15.113393522 +0200
+++ new/test/hotspot/jtreg/gc/logging/TestUnifiedLoggingSwitchStress.java	2018-06-01 23:13:14.855382515 +0200
@@ -42,6 +42,7 @@
  * @key gc stress
  * @summary Switches gc log level on fly while stressing memory/gc
  * @requires !vm.flightRecorder
+ * @requires vm.gc != "Z"
  * @library /test/lib /
  * @modules java.management java.base/jdk.internal.misc
  *