diff --git a/Octokit.Tests/Octokit.Tests.csproj b/Octokit.Tests/Octokit.Tests.csproj
index 6f2f5ee2..c29287f3 100644
--- a/Octokit.Tests/Octokit.Tests.csproj
+++ b/Octokit.Tests/Octokit.Tests.csproj
@@ -116,6 +116,7 @@
     <Compile Include="Reactive\ObservableIssueCommentsClientTests.cs" />
     <Compile Include="Reactive\ObservableIssuesClientTests.cs" />
     <Compile Include="Reactive\ObservableMilestonesClientTests.cs" />
+    <Compile Include="Reactive\ObservableOrganizationMembersClientTests.cs" />
     <Compile Include="Reactive\ObservableRepositoriesClientTests.cs" />
     <Compile Include="SimpleJsonSerializerTests.cs" />
     <Compile Include="Clients\UsersClientTests.cs" />
diff --git a/Octokit.Tests/Reactive/ObservableOrganizationMembersClientTests.cs b/Octokit.Tests/Reactive/ObservableOrganizationMembersClientTests.cs
new file mode 100644
index 00000000..9b27ea7f
--- /dev/null
+++ b/Octokit.Tests/Reactive/ObservableOrganizationMembersClientTests.cs
@@ -0,0 +1,189 @@
+using NSubstitute;
+using Octokit;
+using Octokit.Internal;
+using Octokit.Reactive;
+using Octokit.Tests.Helpers;
+using System;
+using System.Collections.Generic;
+using System.Reactive.Linq;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Octokit.Tests.Reactive
+{
+    public class ObservableOrganizationMembersClientTests
+    {
+        public class TheGetAllMethod
+        {
+            [Fact]
+            public void RequestsCorrectUrl()
+            {
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableOrganizationMembersClient(gitHubClient);
+
+                client.GetAll("org");
+
+                gitHubClient.Connection.GetAsync<IReadOnlyList<User>>(
+                    new Uri("orgs/org/members", UriKind.Relative), null, null);
+            }
+
+            [Fact]
+            public async Task EnsuresNonNullArguments()
+            {
+                var client = new ObservableOrganizationMembersClient(Substitute.For<IGitHubClient>());
+
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.GetAll(null));
+                await AssertEx.Throws<ArgumentException>(async () => await client.GetAll(""));
+            }
+        }
+
+        public class TheGetPublicMethod
+        {
+            [Fact]
+            public void RequestsTheCorrectUrl()
+            {
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableOrganizationMembersClient(gitHubClient);
+
+                client.GetPublic("org");
+
+                gitHubClient.Connection.GetAsync<IReadOnlyList<User>>(
+                    new Uri("orgs/org/public_members", UriKind.Relative), null, null);
+            }
+
+            [Fact]
+            public async Task EnsuresNonNullArguments()
+            {
+                var client = new ObservableOrganizationMembersClient(Substitute.For<IGitHubClient>());
+
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.GetPublic(null));
+                await AssertEx.Throws<ArgumentException>(async () => await client.GetPublic(""));
+            }
+        }
+
+        public class TheCheckMemberMethod
+        {
+            [Fact]
+            public void ChecksMemberFromClientOrganizationMember()
+            {
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableOrganizationMembersClient(gitHubClient);
+
+                client.CheckMember("org", "user");
+
+                gitHubClient.Organization.Member.Received().CheckMember("org", "user");
+            }
+
+            [Fact]
+            public async Task EnsuresNonNullArguments()
+            {
+                var client = new ObservableOrganizationMembersClient(Substitute.For<IGitHubClient>());
+
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.CheckMember(null, "username"));
+                await AssertEx.Throws<ArgumentException>(async () => await client.CheckMember("", "username"));
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.CheckMember("org", null));
+                await AssertEx.Throws<ArgumentException>(async () => await client.CheckMember("org", ""));
+            }
+        }
+
+        public class TheCheckMemberPublicMethod
+        {
+            [Fact]
+            public void ChecksMemberPublicFromClientOrganizationMember()
+            {
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableOrganizationMembersClient(gitHubClient);
+
+                client.CheckMemberPublic("org", "user");
+
+                gitHubClient.Organization.Member.Received().CheckMemberPublic("org", "user");
+            }
+
+            [Fact]
+            public async Task EnsuresNonNullArguments()
+            {
+                var client = new ObservableOrganizationMembersClient(Substitute.For<IGitHubClient>());
+
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.CheckMemberPublic(null, "username"));
+                await AssertEx.Throws<ArgumentException>(async () => await client.CheckMemberPublic("", "username"));
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.CheckMemberPublic("org", null));
+                await AssertEx.Throws<ArgumentException>(async () => await client.CheckMemberPublic("org", ""));
+            }
+        }
+
+        public class TheDeleteMethod
+        {
+            [Fact]
+            public void DeletesFromClientOrganizationMember()
+            {
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableOrganizationMembersClient(gitHubClient);
+
+                client.Delete("org", "user");
+
+                gitHubClient.Organization.Member.Received().Delete("org", "user");
+            }
+
+            [Fact]
+            public async Task EnsuresNonNullArguments()
+            {
+                var client = new ObservableOrganizationMembersClient(Substitute.For<IGitHubClient>());
+
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.Delete(null, "username"));
+                await AssertEx.Throws<ArgumentException>(async () => await client.Delete("", "username"));
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.Delete("org", null));
+                await AssertEx.Throws<ArgumentException>(async () => await client.Delete("org", ""));
+            }
+        }
+
+        public class ThePublicizeMethod
+        {
+            [Fact]
+            public void PublicizeFromClientOrganizationMember()
+            {
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableOrganizationMembersClient(gitHubClient);
+
+                client.Publicize("org", "user");
+
+                gitHubClient.Organization.Member.Received().Publicize("org", "user");
+            }
+
+            [Fact]
+            public async Task EnsuresNonNullArguments()
+            {
+                var client = new ObservableOrganizationMembersClient(Substitute.For<IGitHubClient>());
+
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.Publicize(null, "username"));
+                await AssertEx.Throws<ArgumentException>(async () => await client.Publicize("", "username"));
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.Publicize("org", null));
+                await AssertEx.Throws<ArgumentException>(async () => await client.Publicize("org", ""));
+            }
+        }
+
+        public class TheConcealMethod
+        {
+            [Fact]
+            public void ConcealFromClientOrganizationMember()
+            {
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableOrganizationMembersClient(gitHubClient);
+
+                client.Conceal("org", "user");
+
+                gitHubClient.Organization.Member.Received().Conceal("org", "user");
+            }
+
+            [Fact]
+            public async Task EnsuresNonNullArguments()
+            {
+                var client = new ObservableOrganizationMembersClient(Substitute.For<IGitHubClient>());
+
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.Conceal(null, "username"));
+                await AssertEx.Throws<ArgumentException>(async () => await client.Conceal("", "username"));
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.Conceal("org", null));
+                await AssertEx.Throws<ArgumentException>(async () => await client.Conceal("org", ""));
+            }
+        }
+    }
+}