diff --git a/src/SmallInjector.Tests/SmallInjector.Tests.csproj b/src/SmallInjector.Tests/SmallInjector.Tests.csproj
index cbb7690..30590cf 100644
--- a/src/SmallInjector.Tests/SmallInjector.Tests.csproj
+++ b/src/SmallInjector.Tests/SmallInjector.Tests.csproj
@@ -16,4 +16,8 @@
     <PackageReference Include="coverlet.collector" Version="3.1.2" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\SmallInjector\SmallInjector.csproj" />
+  </ItemGroup>
+
 </Project>
diff --git a/src/SmallInjector.Tests/UnitTest1.cs b/src/SmallInjector.Tests/UnitTest1.cs
index 70f5c64..48450e1 100644
--- a/src/SmallInjector.Tests/UnitTest1.cs
+++ b/src/SmallInjector.Tests/UnitTest1.cs
@@ -1,20 +1,17 @@
-namespace SmallInjector.Tests
+namespace SmallInjector.Tests;
+
+public class Tests
 {
-    public class Tests
+    [SetUp]
+    public void Setup() { }
+
+    [Test]
+    public void TestInstatiationAndRegistering()
     {
-        [SetUp]
-        public void Setup() { }
-
-        [Test]
-        public void Test1()
-        {
-            Assert.Pass();
-        }
-
-        [Test]
-        public void Test2()
-        {
-            Assert.Fail();
-        }
+        IContainer container = new Container();
+        container.RegisterType(true, container);
+        Assert.That(container.IsRegistered(typeof(IContainer)), Is.True);
+        var resolved = container.Resolve<IContainer>();
+        Assert.That(resolved, Is.EqualTo(container));
     }
 }
diff --git a/src/SmallInjector/Container.cs b/src/SmallInjector/Container.cs
index c3f8f91..f6d4731 100644
--- a/src/SmallInjector/Container.cs
+++ b/src/SmallInjector/Container.cs
@@ -12,7 +12,7 @@ public class Container : IContainer
     {
         if (!IsRegistered<TInterface>())
         {
-            _container[typeof(TInterface)] = new List<RegisteredType> { new RegisteredType(typeof(TService), isSingleton, null) };
+            _container[typeof(TInterface)] = new List<RegisteredType> { new RegisteredType(typeof(TService), isSingleton, instance) };
         }
         else
         {