diff --git a/Octokit.Tests/Octokit.Tests.csproj b/Octokit.Tests/Octokit.Tests.csproj
index f82e598e..67d9bfc2 100644
--- a/Octokit.Tests/Octokit.Tests.csproj
+++ b/Octokit.Tests/Octokit.Tests.csproj
@@ -213,9 +213,12 @@
     <Compile Include="Reactive\ObservableBlobClientTests.cs" />
     <Compile Include="Reactive\ObservableCommitCommentReactionClientTests.cs" />
     <Compile Include="Reactive\ObservableCommitsClientTests.cs" />
+    <Compile Include="Reactive\ObservableIssueCommentReactionsClientTests.cs" />
+    <Compile Include="Reactive\ObservableIssueReactionsClientTests.cs" />
     <Compile Include="Reactive\ObservableOrganizationsClientTests.cs" />
     <Compile Include="Reactive\ObservableIssuesLabelsClientTests.cs" />
     <Compile Include="Reactive\ObservablePullRequestReviewCommentReactionsClientTests.cs" />
+    <Compile Include="Reactive\ObservableReactionsClientTests.cs" />
     <Compile Include="Reactive\ObservableRepoCollaboratorsClientTests.cs" />
     <Compile Include="Reactive\ObservableDeploymentsClientTests.cs" />
     <Compile Include="Reactive\ObservableDeploymentStatusClientTests.cs" />
diff --git a/Octokit.Tests/Reactive/ObservableIssueCommentReactionsClientTests.cs b/Octokit.Tests/Reactive/ObservableIssueCommentReactionsClientTests.cs
new file mode 100644
index 00000000..1ae5f48b
--- /dev/null
+++ b/Octokit.Tests/Reactive/ObservableIssueCommentReactionsClientTests.cs
@@ -0,0 +1,65 @@
+using NSubstitute;
+using Octokit.Reactive;
+using System;
+using Xunit;
+
+namespace Octokit.Tests.Reactive
+{
+    public class ObservableIssueCommentReactionsClientTests
+    {
+        public class TheCtor
+        {
+            [Fact]
+            public void EnsuresNonNullArguments()
+            {
+                Assert.Throws<ArgumentNullException>(() => new ObservableIssueCommentReactionsClient(null));
+            }
+        }
+
+        public class TheGetAllMethod
+        {
+            private readonly IGitHubClient _githubClient;
+            private readonly IObservableReactionsClient _client;
+            private const string owner = "owner";
+            private const string name = "name";
+
+            public TheGetAllMethod()
+            {
+                _githubClient = Substitute.For<IGitHubClient>();
+                _client = new ObservableReactionsClient(_githubClient);
+            }
+
+            [Fact]
+            public void RequestsCorrectUrl()
+            {
+                _client.IssueComment.GetAll("fake", "repo", 42);
+                _githubClient.Received().Reaction.IssueComment.GetAll("fake", "repo", 42);
+            }
+
+            [Fact]
+            public void EnsuresArgumentsNotNull()
+            {
+
+                Assert.Throws<ArgumentNullException>(() => _client.IssueComment.Create(null, "name", 1, new NewReaction(ReactionType.Heart)));
+                Assert.Throws<ArgumentException>(() => _client.IssueComment.Create("", "name", 1, new NewReaction(ReactionType.Heart)));
+                Assert.Throws<ArgumentNullException>(() => _client.IssueComment.Create("owner", null, 1, new NewReaction(ReactionType.Heart)));
+                Assert.Throws<ArgumentException>(() => _client.IssueComment.Create("owner", "", 1, new NewReaction(ReactionType.Heart)));
+                Assert.Throws<ArgumentNullException>(() => _client.IssueComment.Create("owner", "name", 1, null));
+            }
+        }
+
+        public class TheCreateMethod
+        {
+            [Fact]
+            public void RequestsCorrectUrl()
+            {
+                var githubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableReactionsClient(githubClient);
+                var newReaction = new NewReaction(ReactionType.Confused);
+
+                client.IssueComment.Create("fake", "repo", 1, newReaction);
+                githubClient.Received().Reaction.IssueComment.Create("fake", "repo", 1, newReaction);
+            }
+        }
+    }
+}
diff --git a/Octokit.Tests/Reactive/ObservableIssueReactionsClientTests.cs b/Octokit.Tests/Reactive/ObservableIssueReactionsClientTests.cs
new file mode 100644
index 00000000..08d51994
--- /dev/null
+++ b/Octokit.Tests/Reactive/ObservableIssueReactionsClientTests.cs
@@ -0,0 +1,65 @@
+using NSubstitute;
+using Octokit.Reactive;
+using System;
+using Xunit;
+
+namespace Octokit.Tests.Reactive
+{
+    public class ObservableIssueReactionsClientTests
+    {
+        public class TheCtor
+        {
+            [Fact]
+            public void EnsuresNonNullArguments()
+            {
+                Assert.Throws<ArgumentNullException>(() => new ObservableIssueReactionsClient(null));
+            }
+        }
+
+        public class TheGetAllMethod
+        {
+            private readonly IGitHubClient _githubClient;
+            private readonly IObservableReactionsClient _client;
+            private const string owner = "owner";
+            private const string name = "name";
+
+            public TheGetAllMethod()
+            {
+                _githubClient = Substitute.For<IGitHubClient>();
+                _client = new ObservableReactionsClient(_githubClient);
+            }
+
+            [Fact]
+            public void RequestsCorrectUrl()
+            {
+                _client.Issue.GetAll("fake", "repo", 42);
+                _githubClient.Received().Reaction.Issue.GetAll("fake", "repo", 42);
+            }
+
+            [Fact]
+            public void EnsuresArgumentsNotNull()
+            {
+
+                Assert.Throws<ArgumentNullException>(() => _client.Issue.Create(null, "name", 1, new NewReaction(ReactionType.Heart)));
+                Assert.Throws<ArgumentException>(() => _client.Issue.Create("", "name", 1, new NewReaction(ReactionType.Heart)));
+                Assert.Throws<ArgumentNullException>(() => _client.Issue.Create("owner", null, 1, new NewReaction(ReactionType.Heart)));
+                Assert.Throws<ArgumentException>(() => _client.Issue.Create("owner", "", 1, new NewReaction(ReactionType.Heart)));
+                Assert.Throws<ArgumentNullException>(() => _client.Issue.Create("owner", "name", 1, null));
+            }
+        }
+
+        public class TheCreateMethod
+        {
+            [Fact]
+            public void RequestsCorrectUrl()
+            {
+                var githubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableReactionsClient(githubClient);
+                var newReaction = new NewReaction(ReactionType.Confused);
+
+                client.Issue.Create("fake", "repo", 1, newReaction);
+                githubClient.Received().Reaction.Issue.Create("fake", "repo", 1, newReaction);
+            }
+        }
+    }
+}
diff --git a/Octokit.Tests/Reactive/ObservableReactionsClientTests.cs b/Octokit.Tests/Reactive/ObservableReactionsClientTests.cs
new file mode 100644
index 00000000..054fe574
--- /dev/null
+++ b/Octokit.Tests/Reactive/ObservableReactionsClientTests.cs
@@ -0,0 +1,35 @@
+using NSubstitute;
+using Octokit.Reactive;
+using System;
+using System.Reactive.Threading.Tasks;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Octokit.Tests.Reactive
+{
+    public class ObservableReactionsClientTests
+    {
+        public class TheCtor
+        {
+            [Fact]
+            public void EnsuresNonNullArguments()
+            {
+                Assert.Throws<ArgumentNullException>(() => new ObservableReactionsClient(null));
+            }
+        }
+
+        public class TheDeleteMethod
+        {
+            [Fact]
+            public void PostsToCorrectUrl()
+            {
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableReactionsClient(gitHubClient);
+
+                client.Delete(13);
+
+                gitHubClient.Reaction.Received().Delete(13);
+            }
+        }
+    }
+}