diff --git a/scripts/_common.sh b/scripts/_common.sh
index e91494b..1d73c1d 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -124,6 +124,18 @@ ynh_check_if_checksum_is_different() {
 	echo "$check"
 }
 
+#=================================================
+#
+# POSTGRES HELPERS
+#
+# Point of contact : Jean-Baptiste Holcroft <jean-baptiste@holcroft.fr>
+#=================================================
+
+# Create a master password and set up global settings
+# Please always call this script in install and restore scripts
+#
+# usage: ynh_psql_test_if_first_run
+
 ynh_psql_test_if_first_run() {
 	if [ -f /etc/yunohost/psql ];
 	then
@@ -144,8 +156,12 @@ ynh_psql_test_if_first_run() {
 		fi
 
 		systemctl start postgresql
-                su --command="psql -c\"ALTER user postgres WITH PASSWORD '${pgsql}'\"" postgres
-		# we can't use peer since YunoHost create users with nologin
+		sudo --login --user=postgres psql -c"ALTER user postgres WITH PASSWORD '$pgsql'" postgres
+
+		# force all user to connect to local database using passwords
+		# https://www.postgresql.org/docs/current/static/auth-pg-hba-conf.html#EXAMPLE-PG-HBA.CONF
+		# Note: we can't use peer since YunoHost create users with nologin
+		#  See: https://github.com/YunoHost/yunohost/blob/unstable/data/helpers.d/user
 		sed -i '/local\s*all\s*all\s*peer/i \
 		local all all password' "$pg_hba"
 		systemctl enable postgresql
@@ -166,7 +182,7 @@ ynh_psql_connect_as() {
 	user="$1"
 	pwd="$2"
 	db="$3"
-	su --command="PGUSER=\"${user}\" PGPASSWORD=\"${pwd}\" psql \"${db}\"" postgres
+	sudo --login --user=postgres PGUSER="$user" PGPASSWORD="$pwd" psql "$db"
 }
 
 # # Execute a command as root user
@@ -176,7 +192,7 @@ ynh_psql_connect_as() {
 # | arg: db - the database to connect to
 ynh_psql_execute_as_root () {
 	sql="$1"
-	su --command="psql" postgres <<< "$sql"
+	sudo --login --user=postgres psql <<< "$sql"
 }
 
 # Execute a command from a file as root user
@@ -187,7 +203,7 @@ ynh_psql_execute_as_root () {
 ynh_psql_execute_file_as_root() {
 	file="$1"
 	db="$2"
-	su -c "psql $db" postgres < "$file"
+	sudo --login --user=postgres psql "$db" < "$file"
 }
 
 # Create a database, an user and its password. Then store the password in the app's config
@@ -210,7 +226,7 @@ ynh_psql_setup_db () {
 	ynh_app_setting_set "$app" psqlpwd "$db_pwd"	# Store the password in the app's config
 }
 
-# Create a database and grant optionnaly privilegies to a user
+# Create a database and grant privilegies to a user
 #
 # usage: ynh_psql_create_db db [user [pwd]]
 # | arg: db - the database name to create
@@ -221,7 +237,7 @@ ynh_psql_create_db() {
 	user="$2"
 	pwd="$3"
 	ynh_psql_create_user "$user" "$pwd"
-	su --command="createdb --owner=\"${user}\" \"${db}\"" postgres
+	sudo --login --user=postgres createdb --owner="$user" "$db"
 }
 
 # Drop a database
@@ -232,8 +248,8 @@ ynh_psql_create_db() {
 ynh_psql_remove_db() {
 	db="$1"
 	user="$2"
-	su --command="dropdb \"${db}\"" postgres
-	ynh_psql_drop_user "${user}"
+	sudo --login --user=postgres dropdb "$db"
+	ynh_psql_drop_user "$user"
 }
 
 # Dump a database
@@ -245,7 +261,7 @@ ynh_psql_remove_db() {
 # | ret: the psqldump output
 ynh_psql_dump_db() {
 	db="$1"
-	su --command="pg_dump \"${db}\"" postgres
+	sudo --login --user=postgres pg_dump "$db"
 }
 
 
@@ -256,7 +272,7 @@ ynh_psql_dump_db() {
 ynh_psql_create_user() {
 	user="$1"
 	pwd="$2"
-        su --command="psql -c\"CREATE USER ${user} WITH PASSWORD '${pwd}'\"" postgres
+        sudo --login --user=postgres psql -c"CREATE USER $user WITH PASSWORD '$pwd'" postgres
 }
 
 # Drop a user
@@ -265,7 +281,7 @@ ynh_psql_create_user() {
 # | arg: user - the user name to drop
 ynh_psql_drop_user() {
 	user="$1"
-	su --command="dropuser \"${user}\"" postgres
+	sudo --login --user=postgres dropuser "$user"
 }
 
 # Send an email to inform the administrator