diff --git a/README.md b/README.md
index 2b8f9b00..5c1e449f 100644
--- a/README.md
+++ b/README.md
@@ -238,7 +238,7 @@ You can either clone the master branch or download the latest zipped version. Be
     
     `RAILS_ENV=production bundle exec rake redmine:plugins:migrate NAME=redmine_dmsf`
 5. The access rights must be set for web server, example: `chown -R www-data:www-data plugins/redmine_dmsf`.
-6. Restart the web server, e.g. `systemctl apache2 restart`
+6. Restart the web server, e.g. `systemctl restart apache2`
 7. You should configure the plugin via Redmine interface: Administration -> Plugins -> DMSF -> Configure.
 8. Don't forget to grant permissions for DMSF in Administration -> Roles and permissions
 9. Assign DMSF permissions to appropriate roles.
diff --git a/app/controllers/dmsf_upload_controller.rb b/app/controllers/dmsf_upload_controller.rb
index e00d6eb2..fba1b671 100644
--- a/app/controllers/dmsf_upload_controller.rb
+++ b/app/controllers/dmsf_upload_controller.rb
@@ -70,7 +70,12 @@ class DmsfUploadController < ApplicationController
     if defined?(EasyExtensions)
       @attachment.skip_description_required = true
     end
-    saved = @attachment.save
+    begin
+      Attachment.skip_callback(:commit, :after, :reuse_existing_file_if_possible)
+      saved = @attachment.save
+    ensure
+      Attachment.set_callback(:commit, :after, :reuse_existing_file_if_possible)
+    end
 
     respond_to do |format|
       format.js