diff --git a/ci/ruby-bind-utils/Dockerfile b/ci/ruby-bind-utils/Dockerfile
index 0a5a13c..143be61 100644
--- a/ci/ruby-bind-utils/Dockerfile
+++ b/ci/ruby-bind-utils/Dockerfile
@@ -4,4 +4,4 @@ MAINTAINER Brian Cunnie <brian.cunnie@gmail.com>
 
 # need ruby to run dns-check.rb & bind-utils for dig & nslookup
 RUN dnf update -y; \
-  dnf install -y ruby bind-utils
+  dnf install -y ruby bind-utils whois