--- old/src/hotspot/share/gc/shared/workgroup.hpp	2018-02-20 09:24:53.544113951 +0100
+++ new/src/hotspot/share/gc/shared/workgroup.hpp	2018-02-20 09:24:53.373106561 +0100
@@ -59,7 +59,7 @@
   const uint _gc_id;
 
  public:
-  AbstractGangTask(const char* name) :
+  explicit AbstractGangTask(const char* name) :
     _name(name),
     _gc_id(GCId::current_or_undefined())
   {}