diff --git a/server.pl b/server.pl
index 87b2a03..ce64c5a 100755
--- a/server.pl
+++ b/server.pl
@@ -291,7 +291,7 @@ handle_post(Request) :-
     union_all(ModifiedFileLists, ModifiedFiles),
     format(user_error, 'Unified modified files: ~w~n', [ModifiedFiles]),
     list_set(CommitList, message, MessageLists),
-    union_all(MessageLists, Messages),
+    list_to_set(MessageLists, Messages),
     format(user_error, 'Unified commit messages: ~w~n', [Messages]),
     list_set(CommitList, added, AddedFileLists),
     union_all(AddedFileLists, AddedFiles),