diff --git a/offsite-power-check.sh b/offsite-power-check.sh
index 15b412bf..330af4a6 100755
--- a/offsite-power-check.sh
+++ b/offsite-power-check.sh
@@ -177,7 +177,7 @@ LOGROTATE(){
 	# PWO_START
 	i=0
 	for folder in $(ls -d ${PW_LOGARCHIVE}/* 2> /dev/null | sort -r); do
-		((i++))
+		i=`expr ${i} + 1`
 		echo "$i - ${folder}"
 		# [ ${i} -gt 6 ] && rm -Rf ${folder}
 	done