--- a/src/hotspot/share/gc/z/zStat.cpp	Thu Mar 28 19:43:59 2019 +0100
+++ b/src/hotspot/share/gc/z/zStat.cpp	Thu Mar 28 19:43:59 2019 +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) {