diff --git a/scripts/upgrade b/scripts/upgrade
index d3fd195..c48c528 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -24,6 +24,8 @@ final_path=$(ynh_app_setting_get --app=$app --key=final_path)
 language=$(ynh_app_setting_get --app=$app --key=language)
 db_name=$(ynh_app_setting_get --app=$app --key=db_name)
 
+config_file=$final_path/include/ost-config.php
+
 #=================================================
 # CHECK VERSION
 #=================================================
@@ -85,7 +87,7 @@ then
 
 	mkdir $tmpdir/plugins
 	rsync -a "$final_path/include/plugins" "$tmpdir/."
-	rsync -a "$final_path/include/ost-config.php" "$tmpdir/."
+	rsync -a "$config_file" "$tmpdir/."
 	ynh_secure_remove --file="$final_path"
 	
 	# Download, check integrity, uncompress and patch the source from app.src
@@ -207,9 +209,9 @@ ynh_replace_string --match_string="__FINALPATH__" --replace_string="$final_path"
 #=================================================
 ynh_print_info --message="Storing the config file checksum..."
 
-ynh_backup_if_checksum_is_different --file="$final_path/include/ost-config.php"
+ynh_backup_if_checksum_is_different --file="$config_file"
 # Recalculate and store the checksum of the file for the next upgrade.
-ynh_store_file_checksum --file="$final_path/include/ost-config.php"
+ynh_store_file_checksum --file="$config_file"
 
 #=================================================
 # GENERIC FINALIZATION