diff --git a/Makefile b/Makefile
index 378cb41..0e2c68d 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,8 @@ tarball: $(RPM_TARBALL_PATH)
 
 .PHONY: install
 install:
-	install --directory $(DESTDIR)$(RPM_SYSCONFDIR)/nginx/conf.d $(DESTDIR)$(RPM_SYSCONFDIR)/certbot $(DESTDIR)$(RPM_UNITDIR)
+	install --directory $(DESTDIR)$(RPM_SYSCONFDIR)/nginx/conf.d $(DESTDIR)$(RPM_SYSCONFDIR)/certbot $(DESTDIR)$(RPM_UNITDIR) $(DESTDIR)$(RPM_SBINDIR)
 	install --target-directory=$(DESTDIR)$(RPM_SYSCONFDIR)/nginx/conf.d conf/nginx/0_security.conf conf/nginx/default.conf
-	install --target-directory=$(DESTDIR)$(RPM_SYSCONFDIR)/certbot conf/certbot/ovh.ini
-	install --target-directory=$(DESTDIR)$(RPM_UNITDIR) conf/systemd/certbot-renew.service conf/systemd/certbot-renew.timer
+	install --mode=600 --target-directory=$(DESTDIR)$(RPM_SYSCONFDIR)/certbot conf/certbot/ovh.ini
+	install --mode=644 --target-directory=$(DESTDIR)$(RPM_UNITDIR) conf/systemd/certbot-renew.service conf/systemd/certbot-renew.timer
+	install --mode=755 --target-directory=$(DESTDIR)$(RPM_SBINDIR) conf/sbin/certbot_renew
diff --git a/conf/sbin/certbot_renew b/conf/sbin/certbot_renew
new file mode 100644
index 0000000..8040385
--- /dev/null
+++ b/conf/sbin/certbot_renew
@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+/usr/bin/env sleep $(($RANDOM % 3600));
+/opt/certbot/bin/pip install --upgrade certbot certbot-nginx certbot-dns-ovh
+/usr/bin/env certbot renew
diff --git a/conf/systemd/certbot-renew.service b/conf/systemd/certbot-renew.service
index 17663e1..0e5c1d6 100644
--- a/conf/systemd/certbot-renew.service
+++ b/conf/systemd/certbot-renew.service
@@ -2,4 +2,4 @@
 Description=Renew certbot certificates
 
 [Service]
-ExecStart=sleep $RANDOM && /opt/certbot/bin/pip install --upgrade certbot certbot-nginx certbot-dns-ovh && certbot renew
+ExecStart=certbot_renew
diff --git a/netoik-rp.spec b/netoik-rp.spec
index f8f793f..2d6802b 100644
--- a/netoik-rp.spec
+++ b/netoik-rp.spec
@@ -22,34 +22,38 @@ Install the reverse proxy called nginx with a predefined configuration and with
 %make_install
 
 %post
-# After install
-if [ $1 == 1 ]; then
-	# Replace secrets in ovh.ini
-	%{_bindir}/env envsubst < %{_sysconfdir}/certbot/ovh.ini > %{_sysconfdir}/certbot/.ovh.ini.swp
-	%{_bindir}/env mv %{_sysconfdir}/certbot/.ovh.ini.swp %{_sysconfdir}/certbot/ovh.ini
+# Replace secrets in ovh.ini
+%{_bindir}/env envsubst < %{_sysconfdir}/certbot/ovh.ini > %{_sysconfdir}/certbot/.ovh.ini.new
+if %{_bindir}/env cmp --silent %{_sysconfdir}/certbot/.ovh.ini.new %{_sysconfdir}/certbot/ovh.ini; then
+	%{_bindir}/env rm %{_sysconfdir/certbot/.ovh.ini.new
+else
+	%{_bindir}/env mv %{_sysconfdir}/certbot/.ovh.ini.new %{_sysconfdir}/certbot/ovh.ini
 	%{_bindir}/env chmod 600 %{_sysconfdir}/certbot/ovh.ini
+fi
 
-	# Create virutal env with certbot
+# Create virtualenv with certot
+if [ ! -d "/opt/certbot" ]; then
 	%{_bindir}/env python3 -m venv /opt/certbot
 	/opt/certbot/bin/pip install --upgrade pip certbot certbot-nginx certbot-dns-ovh
 	%{_bindir}/env ln --symbolic --force --target-directory %{_sbindir} /opt/certbot/bin/certbot
-
-	# Create certificate with certbot
-	%{_bindir}/env certbot certonly --non-interactive --agree-tos --email "samuel.campos@netoik.io" --dns-ovh --dns-ovh-credentials "%{_sysconfdir}/certbot/ovh.ini" -d "*.netoik.io" -d "*.samuel-campos.fr"
-
-  # Create ssl dh params
-  %{_bindir}/env openssl dhparam -out %{_sysconfdir}/letsencrypt/ssl-dhparams.pem 2048
-
-  # Stop services to be sure changes are taken in account
-  %{_bindir}/env systemctl stop nginx certbot-renew
 fi
 
-# Start services
+# Create certbot certificates
+if [ ! -d "%{_sysconfdir}/letsencrypt/live/netoik.io" || ! -d "%{_sysconfdir}/letsencrypt/live/samuel-campos.fr" ]; then
+	%{_bindir}/env certbot certonly --non-interactive --agree-tos --email "samuel.campos@netoik.io" --dns-ovh --dns-ovh-credentials "%{_sysconfdir}/certbot/ovh.ini" -d "*.netoik.io" -d "*.samuel-campos.fr"
+fi
+
+# Create ssl dh params if not already exists
+if [ ! -f "%{_sysconfdir}/letsencrypt/ssl-dhparams.pem" ]; then
+	%{_bindir}/env openssl dhparam -out %{_sysconfdir}/letsencrypt/ssl-dhparams.pem 2048
+fi
+
+# Restart services
 %{_bindir}/env systemctl daemon-reload
-%{_bindir}/env systemctl enable --now nginx certbot-renew
+%{_bindir}/env systemctl reenable --now nginx.service certbot-renew.timer
 
 %postun
-# After uninstall
+# Remove folders after uninstall
 if [ $1 == 0 ]; then
   %{_bindir}/env rm --recursive --force /opt/certbot
   %{_bindir}/env rm --recursive --force %{_sysconfdir}/certbot
@@ -66,6 +70,8 @@ fi
 %attr(644, root, root) %{_unitdir}/certbot-renew.timer
 %attr(644, root, root) %{_unitdir}/certbot-renew.service
 
+%attr(755, root, root) %{_sbindir}/certbot_renew
+
 %ghost %attr(755, root, root) %dir /opt/certbot
 %ghost %attr(755, root, root) %{_sbindir}/certbot
 %ghost %attr(755, root, root) %dir %{_sysconfdir}/letsencrypt