diff --git a/README.md b/README.md
index 05f598a..d733487 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,5 @@
 # pac
-PAC scripts for proxies
+
+PAC scripts for proxies.
+
+To generate PAC from the latest IP range list, run `./build.sh` (make sure you have `wget` and Python 3 available).