diff --git a/src/JsonRpc/CompositeHandlersManager.cs b/src/JsonRpc/CompositeHandlersManager.cs
index f4feb00bc..384cc8399 100644
--- a/src/JsonRpc/CompositeHandlersManager.cs
+++ b/src/JsonRpc/CompositeHandlersManager.cs
@@ -36,7 +36,7 @@ public IDisposable Add(JsonRpcHandlerFactory factory, JsonRpcHandlerOptions opti
 
         public IDisposable Add(string method, JsonRpcHandlerFactory factory, JsonRpcHandlerOptions options)
         {
-            var result = _parent.Add(factory, options);
+            var result = _parent.Add(method, factory, options);
             _compositeDisposable.Add(result);
             return result;
         }
diff --git a/test/JsonRpc.Tests/CompositeHandlersManagerTests.cs b/test/JsonRpc.Tests/CompositeHandlersManagerTests.cs
new file mode 100644
index 000000000..7ffe639b4
--- /dev/null
+++ b/test/JsonRpc.Tests/CompositeHandlersManagerTests.cs
@@ -0,0 +1,101 @@
+using System;
+using System.Reactive.Disposables;
+using FluentAssertions;
+using NSubstitute;
+using OmniSharp.Extensions.JsonRpc;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace JsonRpc.Tests
+{
+    public class CompositeHandlersManagerTests : AutoTestBase
+    {
+        public CompositeHandlersManagerTests(ITestOutputHelper testOutputHelper) : base(testOutputHelper)
+        {
+        }
+
+        [Fact]
+        public void Should_Add_Handler_Instance_To_Parent()
+        {
+            var parent = Substitute.For<IHandlersManager>();
+            parent.Add(Arg.Any<IJsonRpcHandler>(), Arg.Any<JsonRpcHandlerOptions>()).Returns(Disposable.Empty);
+
+            var manager = new CompositeHandlersManager(parent);
+            manager.Add(Substitute.For<IJsonRpcHandler>(), new JsonRpcHandlerOptions());
+
+            parent.Received(0).Add(Arg.Any<string>(), Arg.Any<IJsonRpcHandler>(), Arg.Any<JsonRpcHandlerOptions>());
+            parent.Received(1).Add(Arg.Any<IJsonRpcHandler>(), Arg.Any<JsonRpcHandlerOptions>());
+            manager.GetDisposable().Count.Should().Be(1);
+        }
+
+        [Fact]
+        public void Should_Add_Named_Handler_Instance_To_Parent()
+        {
+            var parent = Substitute.For<IHandlersManager>();
+            parent.Add(Arg.Any<string>(), Arg.Any<IJsonRpcHandler>(), Arg.Any<JsonRpcHandlerOptions>()).Returns(Disposable.Empty);
+
+            var manager = new CompositeHandlersManager(parent);
+            manager.Add("mymethod", Substitute.For<IJsonRpcHandler>(), new JsonRpcHandlerOptions());
+
+            parent.Received(0).Add(Arg.Any<IJsonRpcHandler>(), Arg.Any<JsonRpcHandlerOptions>());
+            parent.Received(1).Add("mymethod", Arg.Any<IJsonRpcHandler>(), Arg.Any<JsonRpcHandlerOptions>());
+            manager.GetDisposable().Count.Should().Be(1);
+        }
+
+        [Fact]
+        public void Should_Add_Handler_Factory_To_Parent()
+        {
+            var parent = Substitute.For<IHandlersManager>();
+            parent.Add(Arg.Any<JsonRpcHandlerFactory>(), Arg.Any<JsonRpcHandlerOptions>()).Returns(Disposable.Empty);
+
+            var manager = new CompositeHandlersManager(parent);
+            manager.Add(Substitute.For<JsonRpcHandlerFactory>(), new JsonRpcHandlerOptions());
+
+            parent.Received(0).Add(Arg.Any<string>(), Arg.Any<JsonRpcHandlerFactory>(), Arg.Any<JsonRpcHandlerOptions>());
+            parent.Received(1).Add(Arg.Any<JsonRpcHandlerFactory>(), Arg.Any<JsonRpcHandlerOptions>());
+            manager.GetDisposable().Count.Should().Be(1);
+        }
+
+        [Fact]
+        public void Should_Add_Named_Handler_Factory_To_Parent()
+        {
+            var parent = Substitute.For<IHandlersManager>();
+            parent.Add(Arg.Any<string>(), Arg.Any<JsonRpcHandlerFactory>(), Arg.Any<JsonRpcHandlerOptions>()).Returns(Disposable.Empty);
+
+            var manager = new CompositeHandlersManager(parent);
+            manager.Add("mymethod", Substitute.For<JsonRpcHandlerFactory>(), new JsonRpcHandlerOptions());
+
+            parent.Received(0).Add(Arg.Any<JsonRpcHandlerFactory>(), Arg.Any<JsonRpcHandlerOptions>());
+            parent.Received(1).Add("mymethod", Arg.Any<JsonRpcHandlerFactory>(), Arg.Any<JsonRpcHandlerOptions>());
+            manager.GetDisposable().Count.Should().Be(1);
+        }
+
+        [Fact]
+        public void Should_Add_Handler_Type_To_Parent()
+        {
+            var parent = Substitute.For<IHandlersManager>();
+            parent.Add(Arg.Any<Type>(), Arg.Any<JsonRpcHandlerOptions>()).Returns(Disposable.Empty);
+
+            var manager = new CompositeHandlersManager(parent);
+            manager.Add(Substitute.For<Type>(), new JsonRpcHandlerOptions());
+
+            parent.Received(0).Add(Arg.Any<string>(), Arg.Any<Type>(), Arg.Any<JsonRpcHandlerOptions>());
+            parent.Received(1).Add(Arg.Any<Type>(), Arg.Any<JsonRpcHandlerOptions>());
+            manager.GetDisposable().Count.Should().Be(1);
+        }
+
+        [Fact]
+        public void Should_Add_Named_Handler_Type_To_Parent()
+        {
+            var parent = Substitute.For<IHandlersManager>();
+            parent.Add(Arg.Any<string>(), Arg.Any<Type>(), Arg.Any<JsonRpcHandlerOptions>()).Returns(Disposable.Empty);
+
+            var manager = new CompositeHandlersManager(parent);
+            manager.Add("mymethod", Substitute.For<Type>(), new JsonRpcHandlerOptions());
+
+            parent.Received(0).Add(Arg.Any<Type>(), Arg.Any<JsonRpcHandlerOptions>());
+            parent.Received(1).Add("mymethod", Arg.Any<Type>(), Arg.Any<JsonRpcHandlerOptions>());
+            manager.GetDisposable().Count.Should().Be(1);
+        }
+    }
+}
diff --git a/test/JsonRpc.Tests/TestLanguageServerRegistry.cs b/test/JsonRpc.Tests/TestLanguageServerRegistry.cs
index fc2f46f76..589218062 100644
--- a/test/JsonRpc.Tests/TestLanguageServerRegistry.cs
+++ b/test/JsonRpc.Tests/TestLanguageServerRegistry.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Composition;
 using OmniSharp.Extensions.JsonRpc;
 
 namespace JsonRpc.Tests