diff --git a/README.md b/README.md
index fd5372b..5dfb33c 100644
--- a/README.md
+++ b/README.md
@@ -72,3 +72,5 @@ You can send metrics right from terminal:
 # To StatsD port on Docker
 $ for i in {1..1000}; do echo "test.ping:1|C" | nc -v -u -w1 `docker-machine ip` 8126; done
 ```
+
+Data is kept in `/data/graphite/whisper` directory on the host machine.
diff --git a/docker-compose.yml b/docker-compose.yml
index 22705d4..2442443 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -12,7 +12,7 @@ services:
       - '2004:2004/udp'
       - '7002:7002'
     volumes:
-      - /data/graphite/whisper
+      - /data/graphite/whisper:/data/graphite/whisper
       - /graphite-config
   # Brubeck (StatsD replacement)
   # Aggregates metrics before sending them to Carbon