--- a/src/hotspot/share/gc/shared/workgroup.cpp	Mon Nov 25 12:30:24 2019 +0100
+++ b/src/hotspot/share/gc/shared/workgroup.cpp	Mon Nov 25 12:31:39 2019 +0100
@@ -153,7 +153,7 @@
     // Wait for the coordinator to dispatch a task.
     _start_semaphore->wait();
 
-    uint num_started = Atomic::add(1u, &_started);
+    uint num_started = Atomic::add(&_started, 1u);
 
     // Subtract one to get a zero-indexed worker id.
     uint worker_id = num_started - 1;