diff --git a/test/Microsoft.AspNet.Diagnostics.Tests/DeveloperExceptionPageMiddlewareTest.cs b/test/Microsoft.AspNet.Diagnostics.Tests/DeveloperExceptionPageMiddlewareTest.cs
index 8a4e23b87b..bab6220d0e 100644
--- a/test/Microsoft.AspNet.Diagnostics.Tests/DeveloperExceptionPageMiddlewareTest.cs
+++ b/test/Microsoft.AspNet.Diagnostics.Tests/DeveloperExceptionPageMiddlewareTest.cs
@@ -9,6 +9,7 @@ using System.Linq;
 using System.Reflection;
 using System.Runtime.Versioning;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Builder;
 using Microsoft.AspNet.FileProviders;
@@ -497,6 +498,9 @@ namespace Microsoft.AspNet.Diagnostics
             // Act
             await server.CreateClient().GetAsync("/path");
 
+            // This ensures that all diagnostics are completely written to the diagnostic listener
+            Thread.Sleep(1000);
+
             // Assert
             Assert.NotNull(listener.EndRequest?.HttpContext);
             Assert.Null(listener.HostingUnhandledException?.HttpContext);
diff --git a/test/Microsoft.AspNet.Diagnostics.Tests/ExceptionHandlerTest.cs b/test/Microsoft.AspNet.Diagnostics.Tests/ExceptionHandlerTest.cs
index a6b595c7be..0a939252eb 100644
--- a/test/Microsoft.AspNet.Diagnostics.Tests/ExceptionHandlerTest.cs
+++ b/test/Microsoft.AspNet.Diagnostics.Tests/ExceptionHandlerTest.cs
@@ -7,6 +7,7 @@ using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Net;
+using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Builder;
 using Microsoft.AspNet.Http;
@@ -354,6 +355,9 @@ namespace Microsoft.AspNet.Diagnostics
             // Act
             await server.CreateClient().GetAsync(string.Empty);
 
+            // This ensures that all diagnostics are completely written to the diagnostic listener
+            Thread.Sleep(1000);
+
             // Assert
             Assert.NotNull(listener.EndRequest?.HttpContext);
             Assert.Null(listener.HostingUnhandledException?.HttpContext);