--- a/src/hotspot/share/gc/z/zInitialize.hpp	Mon Oct 28 11:26:00 2019 +0100
+++ b/src/hotspot/share/gc/z/zInitialize.hpp	Mon Oct 28 11:26:53 2019 +0100
@@ -29,6 +29,9 @@
 class ZBarrierSet;
 
 class ZInitialize {
+private:
+  void initialize_os();
+
 public:
   ZInitialize(ZBarrierSet* barrier_set);
 };