diff --git a/src/hotspot/share/gc/z/zMark.cpp b/src/hotspot/share/gc/z/zMark.cpp
index 4f19fc4..d93fdad 100644
--- a/src/hotspot/share/gc/z/zMark.cpp
+++ b/src/hotspot/share/gc/z/zMark.cpp
@@ -140,6 +140,24 @@ public:
   }
 };
 
+class ZMarkConcurrentRootsTask : public ZTask {
+private:
+  ZMark* const             _mark;
+  ZConcurrentRootsIterator _roots;
+
+public:
+  ZMarkConcurrentRootsTask(ZMark* mark) :
+      ZTask("ZMarkConcurrentRootsTask"),
+      _mark(mark),
+      _roots() {}
+
+  virtual void work() {
+    ZMarkBarrierOopClosure</* finalizable */ false> cl;
+    _roots.oops_do(&cl);
+  }
+};
+
+
 void ZMark::start() {
   // Verification
   if (ZVerifyMarking) {
@@ -154,6 +172,11 @@ void ZMark::start() {
   _workers->run_parallel(&task);
 }
 
+void ZMark::mark_concurrent_roots() {
+  ZMarkConcurrentRootsTask task(this);
+  _workers->run_concurrent(&task);
+}
+
 void ZMark::prepare_work() {
   assert(_nworkers == _workers->nconcurrent(), "Invalid number of workers");