diff --git a/test/Autofac.Test/Core/Registration/ExternalRegistrySourceTests.cs b/test/Autofac.Test/Core/Registration/ExternalRegistrySourceTests.cs
index d1eabadef..56a54b198 100644
--- a/test/Autofac.Test/Core/Registration/ExternalRegistrySourceTests.cs
+++ b/test/Autofac.Test/Core/Registration/ExternalRegistrySourceTests.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using Xunit;
 
@@ -14,12 +15,24 @@ public interface IServiceB
         {
         }
 
-        public class ClassA : IServiceA, IServiceB
+        public class ClassA : IServiceA, IServiceB, IDisposable
         {
+            public bool IsDisposed { get; private set; }
+
+            public void Dispose()
+            {
+                IsDisposed = true;
+            }
         }
 
-        public class ClassB : IServiceA
+        public class ClassB : IServiceA, IDisposable
         {
+            public bool IsDisposed { get; private set; }
+
+            public void Dispose()
+            {
+                IsDisposed = true;
+            }
         }
 
         [Fact]
@@ -46,21 +59,42 @@ public void TwoLayersOfExternalRegistration_OnDisposingInnerLayer_OuterLayerRema
 
             // Root has the main registration.
             var root = builder.Build();
+            var rootInstance = root.Resolve<ClassA>();
 
             // Middle has ExternalRegistration pointing upwards.
             var middle = root.BeginLifetimeScope(cb => cb.Register(_ => new object()));
-            middle.Resolve<ClassA>();
+            var middleInstance = middle.Resolve<ClassA>();
 
             // Child has ExternalRegistration pointing upwards.
             var child = middle.BeginLifetimeScope(cb => cb.Register(_ => new object()));
-            child.Resolve<ClassA>();
+            var childInstance = child.Resolve<ClassA>();
+
+            Assert.NotSame(rootInstance, middleInstance);
+            Assert.NotSame(middleInstance, childInstance);
+            Assert.NotSame(rootInstance, childInstance);
 
-            // This should only dispose the registration in child, not the one in middle.
+            // This should only dispose the registration in child, not the one in middle or root.
             child.Dispose();
+            Assert.True(childInstance.IsDisposed);
+            Assert.False(middleInstance.IsDisposed);
+            Assert.False(rootInstance.IsDisposed);
 
             // We check by trying to use the registration in middle.
             // If too much got disposed, this will throw ObjectDisposedException.
-            middle.Resolve<ClassA>();
+            Assert.Same(middleInstance, middle.Resolve<ClassA>());
+            Assert.Same(rootInstance, root.Resolve<ClassA>());
+
+            // Middle and child should now be disposed.
+            middle.Dispose();
+            Assert.True(childInstance.IsDisposed);
+            Assert.True(middleInstance.IsDisposed);
+            Assert.False(rootInstance.IsDisposed);
+
+            // Now all should be disposed.
+            root.Dispose();
+            Assert.True(childInstance.IsDisposed);
+            Assert.True(middleInstance.IsDisposed);
+            Assert.True(rootInstance.IsDisposed);
         }
     }
 }