diff --git a/vanilla_first_setup/views/hostname.py b/vanilla_first_setup/views/hostname.py
index 80504b63..3a205a50 100644
--- a/vanilla_first_setup/views/hostname.py
+++ b/vanilla_first_setup/views/hostname.py
@@ -69,7 +69,7 @@ def __validate_hostname(self, hostname):
         if len(hostname) > 64:
             return False
 
-        lower_ascii = re.compile(r"[a-z]+$")
+        lower_ascii = re.compile(r"[a-z0-9]+$")
 
         dot_parts = hostname.split(".")
         for dot_part in dot_parts: