diff --git a/LICENSE b/LICENSE
index ba80af7..aed8f1f 100644
--- a/LICENSE
+++ b/LICENSE
@@ -8,4 +8,6 @@ but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
-http://www.gnu.org/licenses/
\ No newline at end of file
+http://www.gnu.org/licenses/
+
+Map tiles by [Stamen Design](http://stamen.com "Stamen Design"), under [CC BY 3.0](http://creativecommons.org/licenses/by/3.0 "CC BY 3.0"). Data by [OpenStreetMap](http://openstreetmap.org "OpenStreetMap"), under [CC BY SA](http://creativecommons.org/licenses/by-sa/3.0 "CC BY SA").
\ No newline at end of file