diff --git a/README.md b/README.md
index d632c0a..4e9dc98 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,8 @@ https://realtimedata.waternsw.com.au
 pip install git+http://git.wrl.unsw.edu.au:3000/danh/waternsw-grabber.git
 ```
 
+Firefox is required (ww.firefox.com),
+
 ## Usage ##
 
 ```python