diff --git a/scripts/_common.sh b/scripts/_common.sh
index 944a65e..feab25c 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -8,6 +8,30 @@
 # PERSONAL HELPERS
 #=================================================
 
+upgrade_dolibarr() {
+    ynh_setup_source --source_id="$source_id" --dest_dir="$install_dir" --full_replace=1 \
+        --keep="htdocs/conf/conf.php htdocs/install/install.forced.php"
+    chmod -R o-rwx "$install_dir"
+    chown -R "$app:www-data" "$install_dir"
+
+    # Remove the lock if it exists
+    lock=$install_dir/documents/install.lock
+    if [ -f "$lock" ]; then
+        ynh_secure_remove --file="$lock"
+    fi
+
+    pushd "$install_dir/htdocs/install/"
+        "php$phpversion" upgrade.php "$current_version" "$new_version"
+        ynh_exec_fully_quiet sleep 5
+
+        "php$phpversion" upgrade2.php "$current_version" "$new_version"
+        ynh_exec_fully_quiet sleep 5
+
+        "php$phpversion" step5.php "$current_version" "$new_version"
+        ynh_exec_fully_quiet sleep 5
+    popd
+}
+
 #=================================================
 # EXPERIMENTAL HELPERS
 #=================================================