diff --git a/uscrontab b/uscrontab
index daac27a..ade4890 100755
--- a/uscrontab
+++ b/uscrontab
@@ -358,6 +358,10 @@ function check_pause() {
     return 1
 }
 
+# $USER est requis
+[ -n "$LOGNAME" ] || export LOGNAME="$(id -un)"
+[ -n "$USER" ] || export USER="$LOGNAME"
+
 USCRONTAB_CTLINE="* * * * * $script"
 USCRONTAB_LOCKDELAY=8
 USCRONTAB_STOPEC=101