diff --git a/README.md b/README.md
index 8ea9fc5..6fda2dd 100644
--- a/README.md
+++ b/README.md
@@ -77,6 +77,10 @@ dokku redis:link lolipop playground
 #   REDIS_PORT_6379_TCP_PORT=6379
 #   REDIS_PORT_6379_TCP_ADDR=172.17.0.1
 
+# you can examine the environment variables
+# using our 'playground' app's env command
+dokku run playground env
+
 # you can customize the environment
 # variables through a custom docker link alias
 dokku redis:alias lolipop REDIS_DATABASE