diff --git a/Web/lib/MJB/Web/Controller/Blog.pm b/Web/lib/MJB/Web/Controller/Blog.pm
index 3abdbe5..ce8f259 100644
--- a/Web/lib/MJB/Web/Controller/Blog.pm
+++ b/Web/lib/MJB/Web/Controller/Blog.pm
@@ -21,11 +21,17 @@ sub do_create ($c) {
         push @{$c->stash->{errors}}, "You must enter a subdomain."
             unless $subdomain;
 
+        $subdomain = lc($subdomain);
+
+        push @{$c->stash->{errors}}, "Your subdomain may only contain letters, numbers and hypens."
+            unless $subdomain =~ /^[a-z0-9-]+$/;
+
     } elsif ( $domain_type eq 'owned' ) {
         push @{$c->stash->{errors}}, "You must enter a domain."
             unless $domain;
     }
 
+
     return if $c->stash->{errors};
 
     $domain = $domain ? $domain : $subdomain . '.' . $c->config->{customer_domain};