diff --git a/scripts/upgrade b/scripts/upgrade
index 0536151..16e94b2 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -98,7 +98,8 @@ nonfreepackagelist=$(dpkg-query -W -f='${Section}\t${Package}\n' | grep ^non-fre
 if [ $(echo $nonfreepackagelist | wc -l) -eq 1 ] && [ $(echo $nonfreepackagelist | grep -c "snmp-mibs-downloader") -eq 1 ] ;then 
 	ynh_print_info "Removing snmp-mibs-downloader (non-free package)"
 	#want backup file , cannot use ynh_replace_string 
-    sed --in-place==.$(date "+%m%d%y") 's/ snmp-mibs-downloader,//g' /var/lib/dpkg/status
+	cp /var/lib/dpkg/status{,.$(date "+%m%d%y")}
+    ynh_replace_string --match_string=" snmp-mibs-downloader," --replace_string="" --target_file=/var/lib/dpkg/status
     DEBIAN_FRONTEND=noninteractive apt purge snmp-mibs-downloader -y
     if [ -f /etc/apt/sources.list.d/non-free.list ];then
         ynh_secure_remove /etc/apt/sources.list.d/non-free.list