diff --git a/check_process b/check_process
index 8d88180..3c0df0d 100644
--- a/check_process
+++ b/check_process
@@ -13,6 +13,7 @@
 		setup_public=0
 		upgrade=1
 		upgrade=1	from_commit=c864e086625363d91dde6ba78a652011a991a027
+		upgrade=1	from_commit=e9e7015ed7667352c1c191fc632a9f6f382dd9d2
 		backup_restore=1
 		multi_instance=1
 		incorrect_path=1
@@ -25,3 +26,6 @@ Notification=none
 	; commit=c864e086625363d91dde6ba78a652011a991a027
 		name=[fix] php7.2-mcrypt doesn't exist (#253)
 		manifest_arg=domain=DOMAIN&path=PATH&admin=USER&user_home=1&
+	; commit=e9e7015ed7667352c1c191fc632a9f6f382dd9d2
+		name=[fix] Upgrade to 20.0.4 (#346)
+		manifest_arg=domain=DOMAIN&path=PATH&admin=USER&user_home=1&
\ No newline at end of file
diff --git a/manifest.json b/manifest.json
index ccc8955..51ab208 100644
--- a/manifest.json
+++ b/manifest.json
@@ -27,8 +27,7 @@
     "multi_instance": true,
     "services": [
         "nginx",
-        "php7.3-fpm",
-        "mysql"
+        "php7.3-fpm"
     ],
     "arguments": {
         "install" : [
diff --git a/scripts/_common.sh b/scripts/_common.sh
index c4e3403..d545d90 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -3,10 +3,10 @@
 # COMMON VARIABLES
 #=================================================
 
-pkg_dependencies="imagemagick acl tar smbclient at"
+pkg_dependencies="imagemagick acl tar smbclient at postgresql"
 
 YNH_PHP_VERSION="7.3"
-extra_php_dependencies="php${YNH_PHP_VERSION}-bz2 php${YNH_PHP_VERSION}-imap php${YNH_PHP_VERSION}-smbclient php${YNH_PHP_VERSION}-gmp php${YNH_PHP_VERSION}-gd php${YNH_PHP_VERSION}-json php${YNH_PHP_VERSION}-intl php${YNH_PHP_VERSION}-curl php${YNH_PHP_VERSION}-apcu php${YNH_PHP_VERSION}-redis php${YNH_PHP_VERSION}-ldap php${YNH_PHP_VERSION}-imagick php${YNH_PHP_VERSION}-zip php${YNH_PHP_VERSION}-mbstring php${YNH_PHP_VERSION}-xml php${YNH_PHP_VERSION}-mysql php${YNH_PHP_VERSION}-igbinary php${YNH_PHP_VERSION}-bcmath"
+extra_php_dependencies="php${YNH_PHP_VERSION}-bz2 php${YNH_PHP_VERSION}-imap php${YNH_PHP_VERSION}-smbclient php${YNH_PHP_VERSION}-gmp php${YNH_PHP_VERSION}-gd php${YNH_PHP_VERSION}-json php${YNH_PHP_VERSION}-intl php${YNH_PHP_VERSION}-curl php${YNH_PHP_VERSION}-apcu php${YNH_PHP_VERSION}-redis php${YNH_PHP_VERSION}-ldap php${YNH_PHP_VERSION}-imagick php${YNH_PHP_VERSION}-zip php${YNH_PHP_VERSION}-mbstring php${YNH_PHP_VERSION}-xml php${YNH_PHP_VERSION}-igbinary php${YNH_PHP_VERSION}-bcmath php${YNH_PHP_VERSION}-pgsql"
 
 #=================================================
 # EXPERIMENTAL HELPERS
diff --git a/scripts/backup b/scripts/backup
index 7ed3c7f..10e0fd8 100755
--- a/scripts/backup
+++ b/scripts/backup
@@ -52,11 +52,11 @@ ynh_backup --src_path="/etc/nginx/conf.d/$domain.d/$app.conf"
 ynh_backup --src_path="/etc/php/$phpversion/fpm/pool.d/$app.conf"
 
 #=================================================
-# BACKUP THE MYSQL DATABASE
+# BACKUP THE POSTGRESQL DATABASE
 #=================================================
-ynh_print_info --message="Backing up the MySQL database..."
+ynh_print_info --message="Backing up the PostgreSQL database..."
 
-ynh_mysql_dump_db --database="$db_name" > db.sql
+ynh_psql_dump_db --database="$db_name" > db.sql
 
 #=================================================
 # SPECIFIC BACKUP
diff --git a/scripts/install b/scripts/install
index bb5e844..28655ee 100755
--- a/scripts/install
+++ b/scripts/install
@@ -58,13 +58,14 @@ ynh_script_progression --message="Installing dependencies..." --weight=10
 ynh_install_app_dependencies $pkg_dependencies
 
 #=================================================
-# CREATE A MYSQL DATABASE
+# CREATE A POSTGRESQL DATABASE
 #=================================================
-ynh_script_progression --message="Creating a MySQL database..." --weight=2
+ynh_script_progression --message="Creating a PostgreSQL database..." --weight=2
 
 db_name=$(ynh_sanitize_dbid --db_name=$app)
 ynh_app_setting_set --app=$app --key=db_name --value=$db_name
-ynh_mysql_setup_db --db_user=$db_name --db_name=$db_name
+ynh_psql_test_if_first_run
+ynh_psql_setup_db --db_user=$db_name --db_name=$db_name
 
 #=================================================
 # DOWNLOAD, CHECK AND UNPACK SOURCE
@@ -156,7 +157,7 @@ admin_password="$(ynh_string_random --length=6)"
 
 # Install Nextcloud using a temporary admin user
 exec_occ maintenance:install \
-    --database "mysql" --database-name $db_name \
+    --database "pgsql" --database-name $db_name \
     --database-user $db_name --database-pass "$db_pwd" \
     --admin-user "admin" --admin-pass "$admin_password" \
     --data-dir "$datadir" \
@@ -252,7 +253,7 @@ exec_occ config:system:set overwrite.cli.url --value="https://${domain}"
 #=================================================
 
 # Set the user as admin
-ynh_mysql_connect_as --user=$db_name --password="$db_pwd" --database=$db_name \
+ynh_psql_connect_as --user=$db_name --password="$db_pwd" --database=$db_name \
     <<< "INSERT INTO oc_group_user VALUES ('admin','$admin');"
 # And delete admin user
 exec_occ user:delete admin
diff --git a/scripts/remove b/scripts/remove
index b84d5bf..4c3e371 100755
--- a/scripts/remove
+++ b/scripts/remove
@@ -31,12 +31,12 @@ ynh_script_progression --message="Removing dependencies..." --weight=20
 ynh_remove_app_dependencies
 
 #=================================================
-# REMOVE THE MYSQL DATABASE
+# REMOVE THE POSTGRESQL DATABASE
 #=================================================
-ynh_script_progression --message="Removing the MySQL database..." --weight=5
+ynh_script_progression --message="Removing the PostgreSQL database..." --weight=5
 
 # Remove a database if it exists, along with the associated user
-ynh_mysql_remove_db --db_user=$db_name --db_name=$db_name
+ynh_psql_remove_db --db_user=$db_name --db_name=$db_name
 
 #=================================================
 # REMOVE APP MAIN DIR
diff --git a/scripts/restore b/scripts/restore
index 44f8384..8e6f5ee 100755
--- a/scripts/restore
+++ b/scripts/restore
@@ -44,6 +44,14 @@ test ! -d $final_path \
 
 #=================================================
 # STANDARD RESTORATION STEPS
+#=================================================
+# REINSTALL DEPENDENCIES
+#=================================================
+ynh_script_progression --message="Reinstalling dependencies..." --weight=10
+
+# Define and install dependencies
+ynh_install_app_dependencies $pkg_dependencies
+
 #=================================================
 # RESTORE THE NGINX CONFIGURATION
 #=================================================
@@ -67,13 +75,15 @@ ynh_script_progression --message="Restoring the app main directory..."
 ynh_restore_file --origin_path="$final_path"
 
 #=================================================
-# RESTORE THE MYSQL DATABASE
+# RESTORE THE POSTGRESQL DATABASE
 #=================================================
-ynh_script_progression --message="Restoring the MySQL database..." --weight=9
+ynh_script_progression --message="Restoring the PostgreSQL database..." --weight=9
 
-db_pwd=$(ynh_app_setting_get --app=$app --key=mysqlpwd)
-ynh_mysql_setup_db --db_user=$db_name --db_name=$db_name --db_pwd=$db_pwd
-ynh_mysql_connect_as --user=$db_name --password=$db_pwd --database=$db_name < ./db.sql
+ynh_psql_test_if_first_run
+db_pwd=$(ynh_app_setting_get --app=$app --key=psqlpwd)
+ynh_psql_setup_db --db_user=$db_name --db_name=$db_name --db_pwd=$db_pwd
+# Restore dump
+ynh_psql_connect_as --user=$db_name --password=$db_pwd --database=$db_name < ./db.sql
 
 #=================================================
 # RECREATE THE DEDICATED USER
@@ -85,14 +95,6 @@ ynh_system_user_create --username=$app
 
 #=================================================
 # SPECIFIC RESTORATION
-#=================================================
-# REINSTALL DEPENDENCIES
-#=================================================
-ynh_script_progression --message="Reinstalling dependencies..." --weight=10
-
-# Define and install dependencies
-ynh_install_app_dependencies $pkg_dependencies
-
 #=================================================
 # RESTORE THE PHP-FPM CONFIGURATION
 #=================================================
diff --git a/scripts/upgrade b/scripts/upgrade
index 39b124d..3baf8b0 100755
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -94,6 +94,9 @@ then
     ynh_app_setting_delete $app backup_core_only
 
     ynh_clean_setup () {
+        # Remove both databases in case script fails during database migration
+        ynh_exec_warn_less ynh_psql_remove_db --db_user=$db_name --db_name=$db_name
+        ynh_exec_warn_less ynh_mysql_remove_db --db_user=$db_name --db_name=$db_name
         # restore it if the upgrade fails
         ynh_restore_upgradebackup
     }
@@ -211,6 +214,28 @@ local mount_id=$(exec_occ files_external:create --output=json \
 # Define app's data directory
 datadir="/home/yunohost.app/$app/data"
 
+#=================================================
+# HANDLE DATABASE MIGRATION
+#=================================================
+
+mysql_db_pwd=$(ynh_app_setting_get --app=$app --key=mysqlpwd)
+if [ -n "$mysql_db_pwd" ]
+then
+    ynh_script_progression --message="Migrate Database..."
+
+    ynh_backup_if_checksum_is_different --file="$final_path/config/config.php"
+
+    ynh_psql_test_if_first_run
+    ynh_psql_setup_db --db_user=$db_name --db_name=$db_name
+
+    exec_occ db:convert-type --all-apps --clear-schema pgsql $db_name 127.0.0.1 $db_name --password=$db_pwd -n
+
+    ynh_mysql_remove_db --db_user=$db_name --db_name=$db_name
+    ynh_app_setting_delete --app=$app --key=mysqlpwd
+
+    ynh_store_file_checksum --file="${final_path}/config/config.php"
+fi
+
 if [ "$upgrade_type" == "UPGRADE_APP" ]
 then
     ynh_script_progression --message="Upgrading Nextcloud..." --weight=3