diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a26c378a4cf590243f15a45e95a5c0fa558f4033..f6b5a405c4b3f4a4424ec6a8a25fc4d5891a16fd 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -3,6 +3,7 @@
 ## Session 1
 - add tuto on how to connect to the Rstudio server hosted at the IFB
 
+
 ## All sessions
 - Write summary of all the commands at the end (what should have been written in the .R file during the session)
 
diff --git a/src/create_users_from_mail.sh b/src/create_users_from_mail.sh
index dad1e488ca0990ffec424a4a796f8237073f4366..2f1fbf0a3971ffa2ed43ff4a33ca7a0a22ba6bae 100755
--- a/src/create_users_from_mail.sh
+++ b/src/create_users_from_mail.sh
@@ -7,9 +7,9 @@ USERMAILS=$@
 for USERMAIL in ${USERMAILS[@]}
 do
   USERNAME=$(echo ${USERMAIL} | sed -E 's/(.*)@.*/\1/')
-  adduser ${USERNAME} --gecos 'First Last,RoomNumber,WorkPhone,HomePhone' --disabled-password
+  adduser ${USERNAME} --gecos 'First Last,RoomNumber,WorkPhone,HomePhone' --disabled-password --force-badname > /dev/null
   PASSWD=$(openssl rand -base64 10)
-  echo "${USERNAME}:${PASSWD}" | chpasswd
+  echo "${USERNAME}:${PASSWD}" | chpasswd > /dev/null
   echo "======================================================================="
   echo "${USERMAIL}:"
   echo "${USERNAME}"