diff --git a/scripts/install b/scripts/install
index 6c7ac51..991a865 100644
--- a/scripts/install
+++ b/scripts/install
@@ -76,7 +76,7 @@ if [ $discovery -eq 1 ]; then
 	ynh_script_progression --message="Configuring firewall..." --time --weight=1
 
 	# Open port 1900 for service auto-discovery
-	if [ ynh_port_available --port=1900 ]; then
+	if [[ $(ynh_port_available --port=1900) -eq 1 ]]; then
 		ynh_exec_warn_less yunohost firewall allow UDP 1900
 		ynh_app_setting_set --app=$app --key=discovery_service --value=1
 	else
@@ -85,7 +85,7 @@ if [ $discovery -eq 1 ]; then
 	fi
 
 	# Open port 7359 for client auto-discovery
-	if [ ynh_port_available --port=7359 ]; then
+	if [[ $(ynh_port_available --port=7359) -eq 1 ]]; then
 		ynh_exec_warn_less yunohost firewall allow UDP 7359
 		ynh_app_setting_set --app=$app --key=discovery_client --value=1
 	else
diff --git a/scripts/remove b/scripts/remove
index 0f35084..83a3d43 100644
--- a/scripts/remove
+++ b/scripts/remove
@@ -74,13 +74,13 @@ ynh_remove_logrotate
 # CLOSE A PORT
 #=================================================
 
-if [ $discovery_server -eq 1 ] && [ yunohost firewall list | grep -q "\- 1900$" ]
+if [[ $discovery_server -eq 1 ]] && yunohost firewall list | grep -q "\- 1900$"
 then
 	ynh_script_progression --message="Closing port 1900..." --time --weight=1
 	ynh_exec_warn_less yunohost firewall disallow UDP 1900
 fi
 
-if [ $discovery_client -eq 1 ] && [ yunohost firewall list | grep -q "\- 7359$" ]
+if [[ $discovery_client -eq 1 ]] && yunohost firewall list | grep -q "\- 7359$"
 then
 	ynh_script_progression --message="Closing port 7359..." --time --weight=1
 	ynh_exec_warn_less yunohost firewall disallow UDP 7359