diff --git a/app/controllers/admin/backups_controller.rb b/app/controllers/admin/backups_controller.rb
index 82aebfc6c..3c7855668 100644
--- a/app/controllers/admin/backups_controller.rb
+++ b/app/controllers/admin/backups_controller.rb
@@ -119,7 +119,7 @@ class Admin::BackupsController < Admin::AdminController
 
     return render status: 415, text: I18n.t("backup.backup_file_should_be_tar_gz") unless /\.(tar\.gz|t?gz)$/i =~ filename
     return render status: 415, text: I18n.t("backup.not_enough_space_on_disk")     unless has_enough_space_on_disk?(total_size)
-    return render status: 415, text: I18n.t("backup.invalid_filename") unless !!(/^[a-zA-Z0-9\._-]+$/ =~ filename)
+    return render status: 415, text: I18n.t("backup.invalid_filename") unless !!(/^[a-zA-Z0-9\._\-]+$/ =~ filename)
 
     file               = params.fetch(:file)
     identifier         = params.fetch(:resumableIdentifier)