diff --git a/Howtonfdump.md b/Howtonfdump.md
index 1fcb6d02..634c2b17 100644
--- a/Howtonfdump.md
+++ b/Howtonfdump.md
@@ -123,7 +123,7 @@ On installe NfSen **et** nfdump à partir des sources :
 # tar zxvf v1.6.18.tar.gz
 # cd nfdump-1.6.18
 # echo 'AC_CONFIG_MACRO_DIRS([m4])' >> configure.ac
-# apt install libcurl4-gnutls-dev libboost-regex-dev libboost-filesystem-dev libboost-system-dev libbz2-1.0 libbz2-dev libbz2-ocaml libbz2-ocaml-dev byacc libtool m4 automake pkg-config
+# apt install libcurl4-gnutls-dev libboost-regex-dev libboost-filesystem-dev libboost-system-dev libbz2-1.0 libbz2-dev libbz2-ocaml libbz2-ocaml-dev byacc libtool m4 automake pkg-config flex
 # ./autogen.sh
 # ./configure --enable-nfprofile --enable-nftrack --enable-influxdb
 # make