diff --git a/functions.sh b/functions.sh
index 7ebd43a..d5ef7a2 100644
--- a/functions.sh
+++ b/functions.sh
@@ -236,10 +236,10 @@ function commandIsWorking {
 # arg2: command
 # arg3: pattern
 function commandStdoutPattern {
-  chroot=$1
-  command=$2
-  shift
-  pattern=$@
+  local chroot=$1
+  local command=$2
+  local pattern="$3"
+
   result=$(chroot ${chroot} bash -c "$command")
   if ( echo -n "$result" | grep -qiE "${pattern}" ) ; then echo -ne "1;" ; else echo -ne "0;" ; fi
 }