diff --git a/app/models/conference.rb b/app/models/conference.rb
index 4416d656..ef7b0935 100644
--- a/app/models/conference.rb
+++ b/app/models/conference.rb
@@ -56,7 +56,7 @@ class Conference < ActiveRecord::Base
                         :end_date
 
   validates_uniqueness_of :short_title
-  validates_format_of :short_title, with: /\A[a-zA-Z0-9_-]*\z/
+  validates_format_of :short_title, with: /\A[a-z0-9_]*\z/
   validates :registration_limit, numericality: { only_integer: true, greater_than_or_equal_to: 0 }
 
   # This validation is needed since a conference with a start date greater than the end date is not possible
diff --git a/app/views/admin/conferences/new.html.haml b/app/views/admin/conferences/new.html.haml
index 80307e4f..882ee143 100644
--- a/app/views/admin/conferences/new.html.haml
+++ b/app/views/admin/conferences/new.html.haml
@@ -5,7 +5,7 @@
         = f.input :title, hint: "The name of your conference as it shall appear throughout the site. Example: 'OpenSUSE Conference 2013'",
                           input_html: { required: 'required' }
         = f.input :short_title, hint: "A short and unique handle for your conference, using only lower-case letters, numbers and underscores. This will be used to identify your conference in URLs etc. Example: 'froscon2011'",
-                                input_html: { required: 'required' }
+                                input_html: { required: 'required', pattern: '[a-z0-9_]+', title: 'Only lower-case letters, numbers and underscores.' }, :prepend => conferences_url + '/'
       = f.inputs 'Scheduling' do
         = f.input :timezone, as: :time_zone, default: Time.zone.name, hint: 'Please select in what time zone your conference will take place.'
         = f.input :start_date, as: :string, input_html: { id: 'conference-start-datepicker', required: 'required' }