diff --git a/README.md b/README.md
index 072d6e6..f6ca506 100644
--- a/README.md
+++ b/README.md
@@ -40,6 +40,7 @@ git clone https://github.com/phetsims/sherpa.git
 git clone https://github.com/phetsims/sun.git
 git clone https://github.com/phetsims/tambo.git
 git clone https://github.com/phetsims/tandem.git
+git clone https://github.com/phetsims/twixt.git
 git clone https://github.com/phetsims/utterance-queue.git
 ```
 (2) Start an http-server