diff --git a/plugins/ruby/codegen.pl b/plugins/ruby/codegen.pl
index 593216d71..8cd06b366 100755
--- a/plugins/ruby/codegen.pl
+++ b/plugins/ruby/codegen.pl
@@ -788,6 +788,7 @@ sub render_item_number {
     my $subtype = $item->getAttribute('ld:subtype');
     my $meta = $item->getAttribute('ld:meta');
     my $initvalue = $item->getAttribute('init-value');
+    $initvalue ||= -1 if $item->getAttribute('refers-to') or $item->getAttribute('ref-target');
     my $typename = $item->getAttribute('type-name');
     undef $typename if ($meta and $meta eq 'bitfield-type');
     my $g = $global_types{$typename} if ($typename);