diff --git a/src/components/forms/SipTrunkForm.js b/src/components/forms/SipTrunkForm.js
index 4b30e91..eab5731 100644
--- a/src/components/forms/SipTrunkForm.js
+++ b/src/components/forms/SipTrunkForm.js
@@ -303,7 +303,7 @@ const SipTrunkForm = props => {
       }
 
       const regIp = /^((25[0-5]|2[0-4][0-9]|[0-1]?[0-9]?[0-9])\.){3}(25[0-5]|2[0-4][0-9]|[0-1]?[0-9]?[0-9])$/;
-      const regFqdn = /^([a-zA-Z][^.]*)(\.[^.]+){2,}$/;
+      const regFqdn = /^([a-zA-Z0-9][^.]*)(\.[^.]+){2,}$/;
       const regFqdnTopLevel = /^([a-zA-Z][^.]*)(\.[^.]+)$/;
       const regPort = /^[0-9]+$/;