diff --git a/src/csharp/Grpc.Core/Channel.cs b/src/csharp/Grpc.Core/Channel.cs
index f2211111f6c0895aadf25aec3f4b68d144bf0d25..886adfec334f8c8711ebedb98346190337a7a6be 100644
--- a/src/csharp/Grpc.Core/Channel.cs
+++ b/src/csharp/Grpc.Core/Channel.cs
@@ -136,7 +136,7 @@ namespace Grpc.Core
                     tcs.SetCanceled();
                 }
             });
-            handle.WatchConnectivityState(lastObservedState, deadlineTimespec, completionQueue, environment.CompletionRegistry, handler);
+            handle.WatchConnectivityState(lastObservedState, deadlineTimespec, completionQueue, handler);
             return tcs.Task;
         }
 
diff --git a/src/csharp/Grpc.Core/GrpcEnvironment.cs b/src/csharp/Grpc.Core/GrpcEnvironment.cs
index acc7b214369f44a7d487cf1c3a7892313adf6514..7fa06bf672ea380ef352cbd80e5cce45e11beaeb 100644
--- a/src/csharp/Grpc.Core/GrpcEnvironment.cs
+++ b/src/csharp/Grpc.Core/GrpcEnvironment.cs
@@ -58,7 +58,6 @@ namespace Grpc.Core
         static ILogger logger = new ConsoleLogger();
 
         readonly GrpcThreadPool threadPool;
-        readonly CompletionRegistry completionRegistry;
         readonly DebugStats debugStats = new DebugStats();
         readonly AtomicCounter cqPickerCounter = new AtomicCounter();
         bool isClosed;
@@ -167,24 +166,12 @@ namespace Grpc.Core
         private GrpcEnvironment()
         {
             GrpcNativeInit();
-            completionRegistry = new CompletionRegistry(this);
 
             var cqCount = customCompletionQueueCount ?? DefaultCompletionQueueCount;
             threadPool = new GrpcThreadPool(this, GetThreadPoolSizeOrDefault(), cqCount);
             threadPool.Start();
         }
 
-        /// <summary>
-        /// Gets the completion registry used by this gRPC environment.
-        /// </summary>
-        internal CompletionRegistry CompletionRegistry
-        {
-            get
-            {
-                return this.completionRegistry;
-            }
-        }
-
         /// <summary>
         /// Gets the completion queues used by this gRPC environment.
         /// </summary>
diff --git a/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs b/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs
index a83deaa26f1b98f1c263e8ffa61858e9dcca5268..62864dff0cb88cc774471aed241cfa449b0599ad 100644
--- a/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs
@@ -82,11 +82,10 @@ namespace Grpc.Core.Internal
             return Native.grpcsharp_channel_check_connectivity_state(this, tryToConnect ? 1 : 0);
         }
 
-        public void WatchConnectivityState(ChannelState lastObservedState, Timespec deadline, CompletionQueueSafeHandle cq,
-            CompletionRegistry completionRegistry, BatchCompletionDelegate callback)
+        public void WatchConnectivityState(ChannelState lastObservedState, Timespec deadline, CompletionQueueSafeHandle cq, BatchCompletionDelegate callback)
         {
             var ctx = BatchContextSafeHandle.Create();
-            completionRegistry.RegisterBatchCompletion(ctx, callback);
+            cq.CompletionRegistry.RegisterBatchCompletion(ctx, callback);
             Native.grpcsharp_channel_watch_connectivity_state(this, lastObservedState, deadline, cq, ctx);
         }
 
diff --git a/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs b/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs
index 4059247e30722ea79499f8cf22a2d32184c2a342..ab2cb3836a70867fe8a345274a06efc1152be6cc 100644
--- a/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs
+++ b/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs
@@ -140,7 +140,7 @@ namespace Grpc.Core.Internal
                     IntPtr tag = ev.tag;
                     try
                     {
-                        var callback = environment.CompletionRegistry.Extract(tag);
+                        var callback = cq.CompletionRegistry.Extract(tag);
                         callback(success);
                     }
                     catch (Exception e)
diff --git a/src/csharp/Grpc.Core/Internal/ServerSafeHandle.cs b/src/csharp/Grpc.Core/Internal/ServerSafeHandle.cs
index 191b412669e019861ec3adfab5ff958af09f76ad..85813027064f47359be46b25bdb3bf8cf5e0736e 100644
--- a/src/csharp/Grpc.Core/Internal/ServerSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/ServerSafeHandle.cs
@@ -72,17 +72,17 @@ namespace Grpc.Core.Internal
             Native.grpcsharp_server_start(this);
         }
     
-        public void ShutdownAndNotify(BatchCompletionDelegate callback, GrpcEnvironment environment)
+        public void ShutdownAndNotify(BatchCompletionDelegate callback, CompletionQueueSafeHandle completionQueue)
         {
             var ctx = BatchContextSafeHandle.Create();
-            environment.CompletionRegistry.RegisterBatchCompletion(ctx, callback);
-            Native.grpcsharp_server_shutdown_and_notify_callback(this, environment.PickCompletionQueue(), ctx);
+            completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, callback);
+            Native.grpcsharp_server_shutdown_and_notify_callback(this, completionQueue, ctx);
         }
 
-        public void RequestCall(BatchCompletionDelegate callback, GrpcEnvironment environment, CompletionQueueSafeHandle completionQueue)
+        public void RequestCall(BatchCompletionDelegate callback, CompletionQueueSafeHandle completionQueue)
         {
             var ctx = BatchContextSafeHandle.Create();
-            environment.CompletionRegistry.RegisterBatchCompletion(ctx, callback);
+            completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, callback);
             Native.grpcsharp_server_request_call(this, completionQueue, ctx).CheckOk();
         }
 
diff --git a/src/csharp/Grpc.Core/Server.cs b/src/csharp/Grpc.Core/Server.cs
index b66de8178924dd613094f4b152953df1c4c9392f..069185e13af9b6da2af5fee9ecaea1174d951d3f 100644
--- a/src/csharp/Grpc.Core/Server.cs
+++ b/src/csharp/Grpc.Core/Server.cs
@@ -34,6 +34,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Linq;
 using System.Threading.Tasks;
 using Grpc.Core.Internal;
 using Grpc.Core.Logging;
@@ -160,7 +161,8 @@ namespace Grpc.Core
                 shutdownRequested = true;
             }
 
-            handle.ShutdownAndNotify(HandleServerShutdown, environment);
+            var cq = environment.CompletionQueues.First();  // any cq will do
+            handle.ShutdownAndNotify(HandleServerShutdown, cq);
             await shutdownTcs.Task.ConfigureAwait(false);
             DisposeHandle();
 
@@ -180,7 +182,8 @@ namespace Grpc.Core
                 shutdownRequested = true;
             }
 
-            handle.ShutdownAndNotify(HandleServerShutdown, environment);
+            var cq = environment.CompletionQueues.First();  // any cq will do
+            handle.ShutdownAndNotify(HandleServerShutdown, cq);
             handle.CancelAllCalls();
             await shutdownTcs.Task.ConfigureAwait(false);
             DisposeHandle();
@@ -254,7 +257,7 @@ namespace Grpc.Core
         {
             if (!shutdownRequested)
             {
-                handle.RequestCall((success, ctx) => HandleNewServerRpc(success, ctx, cq), environment, cq);
+                handle.RequestCall((success, ctx) => HandleNewServerRpc(success, ctx, cq), cq);
             }
         }