diff --git a/app/views/messages/_course_show.html.erb b/app/views/messages/_course_show.html.erb
index 40094b162..f5c2a4211 100644
--- a/app/views/messages/_course_show.html.erb
+++ b/app/views/messages/_course_show.html.erb
@@ -106,7 +106,11 @@
         <%= authoring @topic.created_on, @topic.author %>
       </div>
       <div style="float: right">
-        <%= toggle_link l(:button_reply), "reply", :focus => 'message_content' %>
+        <% if User.current.logged? %>
+            <%= toggle_link l(:button_reply), "reply", :focus => 'message_content' %>
+        <% else %>
+            <%= link_to l(:button_reply), signin_path %>
+        <% end %>
       </div>
     </div>
   </div>
diff --git a/app/views/messages/_project_show.html.erb b/app/views/messages/_project_show.html.erb
index 98a1a5767..b0a593180 100644
--- a/app/views/messages/_project_show.html.erb
+++ b/app/views/messages/_project_show.html.erb
@@ -111,7 +111,11 @@
         <%= authoring @topic.created_on, @topic.author %>
       </div>
       <div style="float: right">
-        <%= toggle_link l(:button_reply), "reply", :focus => 'message_content' %>
+        <% if User.current.logged? %>
+            <%= toggle_link l(:button_reply), "reply", :focus => 'message_content' %>
+        <% else %>
+            <%= link_to l(:button_reply), signin_path %>
+        <% end %>
       </div>
     </div>
   </div>