diff --git a/daemons/daemon-util.in b/daemons/daemon-util.in
index b8f6f2bfa0abec11a122ff4e1307e8d6618dfa44..26c650a7e6ec60216a3136d082090601f621d7ed 100755
--- a/daemons/daemon-util.in
+++ b/daemons/daemon-util.in
@@ -116,6 +116,11 @@ fi
 
 orig_action=$1; shift
 
+if [[ "$orig_action" == *_* ]]; then
+  echo "Command must not contain underscores" >&2
+  exit 1
+fi
+
 # Replace all dashes (-) with underlines (_)
 action=${orig_action//-/_}