diff --git a/README.md b/README.md
index 46c12f3..1f79d50 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,7 @@ Installed tools:
 
 - ping
 - traceroute
+- dig
 
 ### Example 1
 
@@ -30,6 +31,7 @@ steps:
     - env
     - ping www.github.com -w 5
     - traceroute -T -p 443 www.github.com
+    - dig www.apple.com
     - echo "end of test"
 ```
 
diff --git a/docker/Dockerfile b/docker/Dockerfile
index afc321e..fe71ef3 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -1,4 +1,4 @@
 FROM ubuntu
 RUN apt-get update
-RUN apt-get install -y traceroute iputils-ping
+RUN apt-get install -y traceroute iputils-ping bind9-dnsutils
 ENTRYPOINT /bin/bash