diff --git a/src/Orchard.Web/Web.config b/src/Orchard.Web/Web.config
index c932164d1..50ddc9ad3 100644
--- a/src/Orchard.Web/Web.config
+++ b/src/Orchard.Web/Web.config
@@ -141,6 +141,8 @@
       <!-- Return 404 for all requests via managed handler. The url routing handler will substitute the mvc request handler when routes match. -->
       <add name="NotFound" path="*" verb="*" type="System.Web.HttpNotFoundHandler" preCondition="integratedMode" requireAccess="Script"/>
     </handlers>
+    <!-- Prevent IIS 7.0 from returning a custom 404/500 error page of its own -->
+    <httpErrors existingResponse="PassThrough" />
   </system.webServer>
   <runtime>
     <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">