diff --git a/Octokit.Tests/Clients/MigrationsClientTests.cs b/Octokit.Tests/Clients/MigrationsClientTests.cs
index 03b99f05eb..a1d610a254 100644
--- a/Octokit.Tests/Clients/MigrationsClientTests.cs
+++ b/Octokit.Tests/Clients/MigrationsClientTests.cs
@@ -8,6 +8,16 @@ namespace Octokit.Tests.Clients
 {
     public class MigrationsClientTests
     {
+        public class TheCtor
+        {
+            [Fact]
+            public void EnsuresNonNullArguments()
+            {
+                Assert.Throws<ArgumentNullException>(
+                    () => new EventsClient(null));
+            }
+        }
+
         public class TheGetMethod
         {
             [Fact]
diff --git a/Octokit.Tests/Reactive/ObservableMigrationsClientTests.cs b/Octokit.Tests/Reactive/ObservableMigrationsClientTests.cs
index 513da13c1e..90be692fc4 100644
--- a/Octokit.Tests/Reactive/ObservableMigrationsClientTests.cs
+++ b/Octokit.Tests/Reactive/ObservableMigrationsClientTests.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using NSubstitute;
 using Octokit.Reactive;
 using Xunit;
@@ -7,6 +8,16 @@ namespace Octokit.Tests.Reactive
 {
     public class ObservableMigrationsClientTests
     {
+        public class TheCtor
+        {
+            [Fact]
+            public void EnsuresNonNullArguments()
+            {
+                Assert.Throws<ArgumentNullException>(
+                    () => new EventsClient(null));
+            }
+        }
+
         public class TheStartMethod
         {
             [Fact]