--- old/src/hotspot/share/gc/z/zStat.cpp	2019-03-27 22:41:26.950903859 +0100
+++ new/src/hotspot/share/gc/z/zStat.cpp	2019-03-27 22:41:26.731896840 +0100
@@ -749,6 +749,11 @@
 }
 
 //
+// Stat timer
+//
+__thread uint32_t ZStatTimerDisable::_active = 0;
+
+//
 // Stat sample/inc
 //
 void ZStatSample(const ZStatSampler& sampler, uint64_t value, bool trace) {