diff --git a/app/views/projects/show.html.slim b/app/views/projects/show.html.slim
index a4bd858a..e652c935 100644
--- a/app/views/projects/show.html.slim
+++ b/app/views/projects/show.html.slim
@@ -16,13 +16,15 @@
       = link_to l(:label_subproject_new), new_project_path(parent_id: @project), class: 'icon icon-add'
     - if User.current.allowed_to? :close_project, @project
       - if @project.active?
+        - confirm_msg = Redmine::VERSION.to_s >= '5.1' ? l(:text_project_close_confirmation, @project.to_s) : l(:text_are_you_sure)
         = link_to l(:button_close),
                   close_project_path(@project),
-                  data: { confirm: l(:text_are_you_sure) }, method: :post, class: 'icon icon-lock'
+                  data: { confirm: - confirm_msg }, method: :post, class: 'icon icon-lock'
       - else
+        - confirm_msg = Redmine::VERSION.to_s >= '5.1' ? l(:text_project_reopen_confirmation, @project.to_s) : l(:text_are_you_sure)
         = link_to l(:button_reopen),
                   reopen_project_path(@project),
-                  data: { confirm: l(:text_are_you_sure) }, method: :post, class: 'icon icon-unlock'
+                  data: { confirm: confirm_msg }, method: :post, class: 'icon icon-unlock'
 
     - if User.current.admin?
       - if @project.archived?
@@ -30,9 +32,10 @@
                   unarchive_project_path(@project, status: params[:status]),
                   method: :post, class: 'icon icon-unlock'
       - else
+        - confirm_msg = Redmine::VERSION.to_s >= '5.1' ? l(:text_project_archive_confirmation, @project.to_s) : l(:text_are_you_sure)
         = link_to l(:button_archive),
                   archive_project_path(@project, status: params[:status]),
-                  data: { confirm: l(:text_are_you_sure) }, method: :post, class: 'icon icon-lock'
+                  data: { confirm: confirm_msg }, method: :post, class: 'icon icon-lock'
       = link_to l(:button_copy), copy_project_path(@project), class: 'icon icon-copy'
       = link_to l(:button_delete), project_path(@project), method: :delete, class: 'icon icon-del'
     - elsif @project.deletable?