diff --git a/host_vars/host.example.org.yml b/host_vars/host.example.org.yml
index 5778282..6f1a1ac 100644
--- a/host_vars/host.example.org.yml
+++ b/host_vars/host.example.org.yml
@@ -20,7 +20,7 @@
 
 # All authorized TCP ports
 #tcp_authorized_ports:
-#  - 22
+#  - '22'
 
 # All incoming authorized IP (all ports and all protocols)
 #ip_authorized: []
diff --git a/roles/client_iptables/README.md b/roles/client_iptables/README.md
index bb85042..0e8a1ad 100644
--- a/roles/client_iptables/README.md
+++ b/roles/client_iptables/README.md
@@ -17,7 +17,7 @@ All variables and default values are defined in `defaults/main.yml` :
 
     # All authorized TCP ports
     tcp_authorized_ports:
-      - 22
+      - '22'
     
     # All authorized UDP ports
     udp_authorized_ports: []
diff --git a/roles/client_iptables/defaults/main.yml b/roles/client_iptables/defaults/main.yml
index f493744..f5c5d24 100644
--- a/roles/client_iptables/defaults/main.yml
+++ b/roles/client_iptables/defaults/main.yml
@@ -3,7 +3,7 @@
 
 # All authorized TCP ports
 tcp_authorized_ports:
-  - 22
+  - '22'
 
 # All authorized UDP ports
 udp_authorized_ports: []