diff --git a/campatmo.py b/campatmo.py
index f4fcb13..a355165 100755
--- a/campatmo.py
+++ b/campatmo.py
@@ -98,7 +98,7 @@ class CampAtmo:
         )
         self.lines_thread.start()
 
-    def stop():
+    def stop(self):
         self.stopped = True
         self.lines_thread.join(2)
         self.background_thread.join(0.5)