diff --git a/www-swagg.pl b/www-swagg.pl
index 83d9759..c9fbc90 100755
--- a/www-swagg.pl
+++ b/www-swagg.pl
@@ -88,7 +88,7 @@ get '/ula6' => sub {
 
         # Cat with the time
         $digesty   = sha1_hex($epoch . $fulleui);
-        ($uniqueid = "fd" . substr $digesty, -10) =~ s/(.{1,4})/$1:/g;
+        ($uniqueid = "fd" . substr $digesty, -10) =~ s/(.{4})/$1:/g;
 
         # Set the ULA
         $ula6 = $uniqueid . ':/48';