diff --git a/src/scripts/lib/monitor-utils.lua b/src/scripts/lib/monitor-utils.lua
index 5a79aaca..455469d8 100644
--- a/src/scripts/lib/monitor-utils.lua
+++ b/src/scripts/lib/monitor-utils.lua
@@ -83,7 +83,7 @@ end
 
 function mutils.clear_cam_data (self, dev_num)
   local dev_cam_data = self.cam_data[dev_num]
-  if not dev_num then
+  if not dev_cam_data then
     return
   end