diff --git a/dronekit/test/sitl/test_channels.py b/dronekit/test/sitl/test_channels.py
index 73132d3ab..44c484353 100644
--- a/dronekit/test/sitl/test_channels.py
+++ b/dronekit/test/sitl/test_channels.py
@@ -151,6 +151,7 @@ def channels_callback(vehicle, name, channels):
     i = 5
     while not result['success'] and i > 0:
         time.sleep(.1)
+        i -= 1
     assert result['success'], 'channels callback should be invoked.'
 
     vehicle.close()