diff --git a/cifscreds.c b/cifscreds.c
index f21a47f..5fbf4e8 100644
--- a/cifscreds.c
+++ b/cifscreds.c
@@ -43,7 +43,8 @@
 /* allowed and disallowed characters for user and domain name */
 #define USER_DISALLOWED_CHARS "\\/\"[]:|<>+=;,?*@"
 #define DOMAIN_ALLOWED_CHARS "abcdefghijklmnopqrstuvwxyz" \
-			     "ABCDEFGHIJKLMNOPQRSTUVWXYZ-."
+			     "ABCDEFGHIJKLMNOPQRSTUVWXYZ-." \
+			     "0123456789"
 
 /* destination keyring */
 #define DEST_KEYRING KEY_SPEC_USER_KEYRING