--- 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())
   {}
--- old/test/hotspot/gtest/gc/shared/test_oopStorage.cpp	2018-02-20 09:24:53.819125836 +0100
+++ new/test/hotspot/gtest/gc/shared/test_oopStorage.cpp	2018-02-20 09:24:53.652118618 +0100
@@ -896,7 +896,7 @@
 
 public:
   Task(const char* name, Storage* storage, VerifyState* vstate) :
-    AbstractGangTask(name, GCId::undefined()),
+    AbstractGangTask(name),
     _state(storage),
     _vstate(vstate)
   {}
@@ -915,7 +915,7 @@
 class OopStorageTestParIteration::TaskUsingOopsDo : public AbstractGangTask {
 public:
   TaskUsingOopsDo(const char* name, OopStorage* storage, VerifyState* vstate) :
-    AbstractGangTask(name, GCId::undefined()),
+    AbstractGangTask(name),
     _state(storage),
     _vstate(vstate)
   {}