diff --git a/modemmanager/files/modemmanager.common b/modemmanager/files/modemmanager.common
index dee9d934a..f91e94af2 100644
--- a/modemmanager/files/modemmanager.common
+++ b/modemmanager/files/modemmanager.common
@@ -5,7 +5,7 @@
 ################################################################################
 
 # If there is no interface that use modemmanager, exit
-[ -n "$(uci -q show network | grep modemmanager)" ] && exit
+[ -z "$(uci -q show network | grep modemmanager)" ] && exit
 
 . /lib/functions.sh
 . /lib/netifd/netifd-proto.sh