diff --git a/scripts/install b/scripts/install
index ba5309c..63528c1 100644
--- a/scripts/install
+++ b/scripts/install
@@ -105,7 +105,7 @@ chown -R "$app": "$final_path"
 #=================================================
 
 # Make app public if necessary
-if [ $is_public -eq "1" ]
+if [ "$is_public" -eq "1" ]
 then
 	# unprotected_uris allows SSO credentials to be passed anyway.
 	ynh_app_setting_set "$app" unprotected_uris "/"
diff --git a/scripts/restore b/scripts/restore
index d482e68..7c3facd 100644
--- a/scripts/restore
+++ b/scripts/restore
@@ -27,17 +27,17 @@ ynh_abort_if_errors
 
 app=$YNH_APP_INSTANCE_NAME
 
-domain=$(ynh_app_setting_get $app domain)
-path_url=$(ynh_app_setting_get $app path)
-final_path=$(ynh_app_setting_get $app final_path)
+domain=$(ynh_app_setting_get "$app" domain)
+path_url=$(ynh_app_setting_get "$app" path)
+final_path=$(ynh_app_setting_get "$app" final_path)
 
 #=================================================
 # CHECK IF THE APP CAN BE RESTORED
 #=================================================
 
-ynh_webpath_available $domain $path_url \
+ynh_webpath_available "$domain" "$path_url" \
 	|| ynh_die "Path not available: ${domain}${path_url}"
-test ! -d $final_path \
+test ! -d "$final_path" \
 || ynh_die "There is already a directory: $final_path "
 
 
diff --git a/scripts/upgrade b/scripts/upgrade
index 747f5a3..2725ef7 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -15,12 +15,12 @@ source /usr/share/yunohost/helpers
 
 app=$YNH_APP_INSTANCE_NAME
 
-domain=$(ynh_app_setting_get $app domain)
-path_url=$(ynh_app_setting_get $app path)
-admin=$(ynh_app_setting_get $app admin)
-is_public=$(ynh_app_setting_get $app is_public)
-final_path=$(ynh_app_setting_get $app final_path)
-language=$(ynh_app_setting_get $app language)
+domain=$(ynh_app_setting_get "$app" domain)
+path_url=$(ynh_app_setting_get "$app" path)
+admin=$(ynh_app_setting_get "$app" admin)
+is_public=$(ynh_app_setting_get "$app" is_public)
+final_path=$(ynh_app_setting_get "$app" final_path)
+language=$(ynh_app_setting_get "$app" language)
 
 #=================================================
 # ENSURE DOWNWARD COMPATIBILITY
@@ -28,23 +28,23 @@ language=$(ynh_app_setting_get $app language)
 
 # Fix is_public as a boolean value
 if [ "$is_public" = "Yes" ]; then
-	ynh_app_setting_set $app is_public 1
+	ynh_app_setting_set "$app" is_public 1
 	is_public=1
 elif [ "$is_public" = "No" ]; then
-	ynh_app_setting_set $app is_public 0
+	ynh_app_setting_set "$app" is_public 0
 	is_public=0
 fi
 
 # If db_name doesn't exist, create it
-if [ -z $db_name ]; then
-	db_name=$(ynh_sanitize_dbid $app)
-	ynh_app_setting_set $app db_name $db_name
+if [ -z "$db_name" ]; then
+	db_name=$(ynh_sanitize_dbid "$app")
+	ynh_app_setting_set "$app" db_name "$db_name"
 fi
 
 # If final_path doesn't exist, create it
-if [ -z $final_path ]; then
-	final_path=/var/www/$app
-	ynh_app_setting_set $app final_path $final_path
+if [ -z "$final_path" ]; then
+	final_path="/var/www/$app"
+	ynh_app_setting_set "$app" final_path "$final_path"
 fi
 
 #=================================================
@@ -65,7 +65,7 @@ ynh_abort_if_errors
 #=================================================
 
 # Normalize the URL path syntax
-path_url=$(ynh_normalize_url_path $path_url)
+path_url=$(ynh_normalize_url_path "$path_url")
 
 #=================================================
 # STANDARD UPGRADE STEPS
@@ -114,7 +114,7 @@ chown -R "$app": "$final_path"
 #=================================================
 
 # Make app public if necessary
-if [ $is_public -eq "1" ]
+if [ "$is_public" -eq "1" ]
 then
 	# unprotected_uris allows SSO credentials to be passed anyway.
 	ynh_app_setting_set "$app" unprotected_uris "/"
@@ -126,4 +126,4 @@ fi
 # RELOAD NGINX
 #=================================================
 
-systemctl reload nginx
+systemctl reload nginx
\ No newline at end of file