diff --git a/telethon/_updates/messagebox.py b/telethon/_updates/messagebox.py
index ea709e87..2014f63d 100644
--- a/telethon/_updates/messagebox.py
+++ b/telethon/_updates/messagebox.py
@@ -329,7 +329,7 @@ class MessageBox:
     # updates will be fetched.
     def set_state(self, state, reset=True):
         if __debug__:
-            self._trace('Setting state %r', state)
+            self._trace('Setting state %s', state)
 
         deadline = next_updates_deadline()