diff --git a/src/Microsoft.AspNet.Routing/IRouteBuilder.cs b/src/Microsoft.AspNet.Routing/IRouteBuilder.cs
index 7da8c5b61d..933aec2324 100644
--- a/src/Microsoft.AspNet.Routing/IRouteBuilder.cs
+++ b/src/Microsoft.AspNet.Routing/IRouteBuilder.cs
@@ -8,7 +8,7 @@ namespace Microsoft.AspNet.Routing
 {
     public interface IRouteBuilder
     {
-        IRouter DefaultHandler { get; }
+        IRouter DefaultHandler { get; set; }
 
         IServiceProvider ServiceProvider { get; }