diff --git a/README.md b/README.md
index bcb8d58..ad2709c 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@ This project is related to the Basic Module *Architecture & Implementation of DB
 * `git`
 * `cmake` (at least version `3.9`)
 * `build-essential`
-* `bison` and `flex` 
+* `bison` and `flex` (and in Ubuntu the package `libfl-dev`)
 
 ## How to build
 ### Option (a): Build into current folder: