diff --git a/README.md b/README.md
index 544defd..e5b9eac 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,8 @@ For additional details on methods and results please go our [manuscript](link to
 ```R
 library(devtools)
 install_github("CancanQi/BronchiCellPred")
+## or 
+install_github("CancanQi/BronchiCellPred",ref="HEAD")
 ```
 
 ## Quick start