diff --git a/Howtonfdump.md b/Howtonfdump.md
index d062fd68..795a4e28 100644
--- a/Howtonfdump.md
+++ b/Howtonfdump.md
@@ -139,6 +139,7 @@ On installe NfSen **et** nfdump à partir des sources :
 # adduser nfsen
 # adduser nfsen www-data
 # chown -R nfsen:www-data /opt/nfsen
+# chmod -R 750 /opt/nfsen
 # apt install libmailtools-perl
 # ldconfig
 # ./install.pl /etc/nfsen.conf