diff --git a/src/Engine-Twitter/Protocols/Twitter/TwitterProtocolManager.cs b/src/Engine-Twitter/Protocols/Twitter/TwitterProtocolManager.cs
index f56635e8a..896091bba 100644
--- a/src/Engine-Twitter/Protocols/Twitter/TwitterProtocolManager.cs
+++ b/src/Engine-Twitter/Protocols/Twitter/TwitterProtocolManager.cs
@@ -1818,6 +1818,9 @@ private void CheckResponse<T>(TwitterResponse<T> response) where T : ITwitterObj
             if (response.Result == RequestResult.Unknown &&
                 response.ErrorMessage == null) {
                 response.ErrorMessage = _("Twitter didn't send a valid response, they're probably overloaded");
+            } else if (response.Result == RequestResult.FileNotFound &&
+                response.ErrorMessage == null) {
+                response.ErrorMessage = _ ("Twitter user not found");
             }
             throw new TwitterizerException(response.ErrorMessage);
         }