diff --git a/app/views/attachments/_form.html.erb b/app/views/attachments/_form.html.erb
index 96c8c6476..51aad0161 100644
--- a/app/views/attachments/_form.html.erb
+++ b/app/views/attachments/_form.html.erb
@@ -30,6 +30,7 @@
         :multiple => multiple,
         :onchange => 'addInputFiles(this);',
         :data => {
+          :max_number_of_files_message => l(:error_attachments_too_many),
           :max_file_size => Setting.attachment_max_size.to_i.kilobytes,
           :max_file_size_message => l(:error_attachment_too_big, :max_size => number_to_human_size(Setting.attachment_max_size.to_i.kilobytes)),
           :max_concurrent_uploads => Redmine::Configuration['max_concurrent_ajax_uploads'].to_i,
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 7bb506c57..96711df83 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -214,6 +214,7 @@ en:
   error_unable_delete_issue_status: 'Unable to delete issue status (%{value})'
   error_unable_to_connect: "Unable to connect (%{value})"
   error_attachment_too_big: "This file cannot be uploaded because it exceeds the maximum allowed file size (%{max_size})"
+  error_attachments_too_many: "This file cannot be uploaded because the maximum number of files that can be attached at the same time has been reached."
   error_session_expired: "Your session has expired. Please login again."
   error_token_expired: "This password recovery link has expired, please try again."
   warning_attachments_not_saved: "%{count} file(s) could not be saved."
diff --git a/public/javascripts/attachments.js b/public/javascripts/attachments.js
index 402cfa53f..567b6be81 100644
--- a/public/javascripts/attachments.js
+++ b/public/javascripts/attachments.js
@@ -29,6 +29,8 @@ function addFile(inputEl, file, eagerUpload) {
 
     addAttachment.toggle(attachmentsFields.children().length < maxFiles);
     return attachmentId;
+  } else {
+    alert($('input.file_selector').data('max-number-of-files-message'));
   }
   return null;
 }