diff --git a/MediaBrowser.Controller/IDisplayPreferencesManager.cs b/MediaBrowser.Controller/IDisplayPreferencesManager.cs
index 87b6f81c5..be1d974a4 100644
--- a/MediaBrowser.Controller/IDisplayPreferencesManager.cs
+++ b/MediaBrowser.Controller/IDisplayPreferencesManager.cs
@@ -48,7 +48,7 @@ namespace MediaBrowser.Controller
         /// <param name="itemId">The item id.</param>
         /// <param name="client">The client string.</param>
         /// <returns>The dictionary of custom item display preferences.</returns>
-        Dictionary<string, string?> ListCustomItemDisplayPreferences(Guid userId, Guid itemId, string client);
+        Dictionary<string, string> ListCustomItemDisplayPreferences(Guid userId, Guid itemId, string client);
 
         /// <summary>
         /// Sets the custom item display preference for the user and client.