--- a/Dockerfile.pngtile	Sat Jul 15 11:56:04 2017 +0300
+++ b/Dockerfile.pngtile	Sat Jul 15 12:06:24 2017 +0300
@@ -29,4 +29,5 @@
   DJANGO_SERVER_NAME= \
   DJANGO_SERVER_ALIAS= \
   DJANGO_SECRET= \
-  QMSK_PNGTILE_PATH=/srv/pngtile/images
+  QMSK_PNGTILE_PATH=/srv/pngtile/images \
+  QMSK_PNGTILE_TILES_URL=