diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index 2c7a9536e76..cba217d01ea 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -899,11 +899,11 @@ en:
       xaxis: "Day"
       yaxis: "Number of Emails"
     user_to_user_private_messages:
-      title: "User-to-User"
+      title: "User-to-User (excluding replies)"
       xaxis: "Day"
       yaxis: "Number of messages"
     user_to_user_private_messages_with_replies:
-      title: "User-to-User (with replies)"
+      title: "User-to-User (including replies)"
       xaxis: "Day"
       yaxis: "Number of messages"
     system_private_messages: