diff --git a/app/views/settings/_mattermost_settings.html.erb b/app/views/settings/_mattermost_settings.html.erb
index ed5f31e..0aab74a 100644
--- a/app/views/settings/_mattermost_settings.html.erb
+++ b/app/views/settings/_mattermost_settings.html.erb
@@ -3,6 +3,11 @@
 	<input type="text" id="settings_mattermost_url" size=80 value="<%= settings['mattermost_url'] %>" name="settings[mattermost_url]" />
 </p>
 
+<p>
+	The URL can be changed on a per-project basis by creating a
+	<a href="/custom_fields/new?type=ProjectCustomField">project custom field</a> named "Mattermost URL" (without quotes).
+</p>
+
 <p>
 	<label for="settings_channel">Mattermost Channel</label>
 	<input type="text" id="settings_channel" value="<%= settings['channel'] %>" name="settings[channel]" />