diff --git a/db/migrate/20130201184705_add_unique_index_on_tokens_value.rb b/db/migrate/20130201184705_add_unique_index_on_tokens_value.rb
new file mode 100644
index 000000000..fdec9f8ee
--- /dev/null
+++ b/db/migrate/20130201184705_add_unique_index_on_tokens_value.rb
@@ -0,0 +1,15 @@
+class AddUniqueIndexOnTokensValue < ActiveRecord::Migration
+  def up
+    say_with_time "Adding unique index on tokens, this may take some time..." do
+      # Just in case
+      duplicates = Token.connection.select_values("SELECT value FROM #{Token.table_name} GROUP BY value HAVING COUNT(id) > 1")
+      Token.where(:value => duplicates).delete_all
+  
+      add_index :tokens, :value, :unique => true, :name => 'tokens_value'
+    end
+  end
+
+  def down
+    remove_index :tokens, :name => 'tokens_value'
+  end
+end