eliminate global completion registry
diff --git a/src/csharp/Grpc.Core/Channel.cs b/src/csharp/Grpc.Core/Channel.cs
index f221111..886adfe 100644
--- a/src/csharp/Grpc.Core/Channel.cs
+++ b/src/csharp/Grpc.Core/Channel.cs
@@ -136,7 +136,7 @@
                     tcs.SetCanceled();
                 }
             });
-            handle.WatchConnectivityState(lastObservedState, deadlineTimespec, completionQueue, environment.CompletionRegistry, handler);
+            handle.WatchConnectivityState(lastObservedState, deadlineTimespec, completionQueue, handler);
             return tcs.Task;
         }