diff --git a/README b/README
index d5d924c4f80b8982d8ccca1e4c883600382d9f07..35360b354b706d39e74dc7ccac2d6ee26b814689 100644
--- a/README
+++ b/README
@@ -10,5 +10,6 @@ Required packages
 - libncurses-dev
 - libssl-dev
 - build-essentials (gcc and GNU Make)
+- libmodbus (used for communicating with the coke machine)
 
 Run `make -C src/`