diff --git a/README.md b/README.md
index 7e16f94..0eabdbc 100644
--- a/README.md
+++ b/README.md
@@ -82,12 +82,12 @@
 
 # Installing more tools
 
-You can run your container as root - and unstall via apt-get, install as part of build steps via jenkins tool installers, or you can create your own Dockerfile to customise, for example: 
+You can run your container as root - and install via apt-get, install as part of build steps via jenkins tool installers, or you can create your own Dockerfile to customise, for example: 
 
 ```
 FROM jenkins
 USER root # if we want to install via apt
-RUN apt-get install -y ruby make more-thing-here
+RUN apt-get update && apt-get install -y ruby make more-thing-here
 USER jenkins # drop back to the regular jenkins user - good practice
 ```