diff --git a/README.md b/README.md
index cddde638281..674635946f3 100644
--- a/README.md
+++ b/README.md
@@ -257,6 +257,7 @@ To reinstall with the latest master, run `brew uninstall openapi-generator && br
 
 To install OpenJDK (pre-requisites), please run
 ```sh
+brew tap AdoptOpenJDK/openjdk
 brew cask install adoptopenjdk12
 export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk-12.0.2.jdk/Contents/Home/
 ```