diff --git a/README.md b/README.md
index d442cf3..341c9b0 100644
--- a/README.md
+++ b/README.md
@@ -273,4 +273,20 @@ conf.probe.target=/srv/statoolinfos/well-known/statoolinfos/foo.bar.org-metrics.
 conf.probe.httpaccesslog.pattern=
 ```
 
-Warning: to have month metric values, you have to set **retention log to 7 weeks or 50 days** in nginx or Apache logrotate configuration.
\ No newline at end of file
+Warning: to have month metric values, you have to set **retention log to 7 weeks or 50 days** in Nginx or Apache logrotate configuration.
+
+Pour Nginx, éditer le fichier `/etc/logrotate.d/nginx` :
+```
+/var/log/nginx/*.log {
+        weekly
+        missingok
+        rotate 7
+```
+
+Pour Apache, éditer le fichier `/etc/logrotate.d/apache2` :
+```
+/var/log/apache2/*.log {
+    weekly
+    missingok
+    rotate 7
+```