diff --git a/MediaBrowser.Common/Configuration/IConfigurationManager.cs b/MediaBrowser.Common/Configuration/IConfigurationManager.cs
index 8cbeaea866..60faaa6172 100644
--- a/MediaBrowser.Common/Configuration/IConfigurationManager.cs
+++ b/MediaBrowser.Common/Configuration/IConfigurationManager.cs
@@ -50,7 +50,7 @@ namespace MediaBrowser.Common.Configuration
         /// Manually pre-loads a factory so that it is available pre system initialisation.
         /// </summary>
         /// <typeparam name="T">Class to register.</typeparam>
-        void RegisterConfiguration<T>();
+        void RegisterConfiguration<T>() where T : IConfigurationFactory;
 
         /// <summary>
         /// Gets the configuration.