diff --git a/src/Umbraco.Web.UI/web.Template.Debug.config b/src/Umbraco.Web.UI/web.Template.Debug.config
index dfbf72173e..3a6633ebab 100644
--- a/src/Umbraco.Web.UI/web.Template.Debug.config
+++ b/src/Umbraco.Web.UI/web.Template.Debug.config
@@ -89,7 +89,7 @@
       </providers>
     </membership>
 
-    <httpRuntime targetFramework="4.5" xdt:Transform="SetAttributes(targetFramework)" />
+    <httpRuntime targetFramework="4.5" fcnMode="Single" xdt:Transform="SetAttributes(targetFramework,fcnMode)" />
 
     <compilation debug="true" targetFramework="4.5" xdt:Transform="SetAttributes(debug,targetFramework)">
       <assemblies xdt:Transform="Remove" />
diff --git a/src/Umbraco.Web.UI/web.Template.config b/src/Umbraco.Web.UI/web.Template.config
index 62e3a00457..17e2dbf755 100644
--- a/src/Umbraco.Web.UI/web.Template.config
+++ b/src/Umbraco.Web.UI/web.Template.config
@@ -79,7 +79,7 @@
   <system.web>
     <customErrors mode="RemoteOnly" />
     <trace enabled="true" requestLimit="10" pageOutput="false" traceMode="SortByTime" localOnly="true" />
-    <httpRuntime requestValidationMode="2.0" enableVersionHeader="false" targetFramework="4.5" />
+    <httpRuntime requestValidationMode="2.0" enableVersionHeader="false" targetFramework="4.5" fcnMode="Single" />
     <!--
       If you are deploying to a cloud environment that has multiple web server instances,
       you should change session state mode from "InProc" to "Custom". In addition,