gistfile1.perl

diff --git a/lib/GraphViz.pm b/lib/GraphViz.pm
index 549c1fd..f69bb58 100644
--- a/lib/GraphViz.pm
+++ b/lib/GraphViz.pm
@@ -1124,17 +1124,12 @@ sub _as_debug {
                 $cluster->{label} = $name;
                 delete $cluster->{name};
             }
-            $attrs = _attributes($cluster);
+            $attrs = _attributes($cluster, for_cluster => 1);
         } else {
             $name = $cluster;
-            $attrs = _attributes( { label => $cluster } );
+            $attrs = _attributes( { label => $cluster }, for_cluster => 1 );
         }
 
-        # rewrite attributes string slightly
-        $attrs =~ s/^\s\[//o;
-        $attrs =~ s/,/;/go;
-        $attrs =~ s/\]$//o;
-
         $dot .= "\tsubgraph cluster_" . $self->_quote_name($name) . " {\n";
         $dot .= "\t\t$attrs;\n";
         $dot .= join "", map {
@@ -1231,6 +1226,7 @@ sub _quote_name {
 
 sub _attributes {
     my $thing = shift;
+    my %opt   = @_;
 
     my @attributes;
 
@@ -1249,6 +1245,7 @@ sub _attributes {
     }
 
     if (@attributes) {
+        return join("; ", sort @attributes) if $opt{for_cluster};
         return ' [' . ( join ', ', sort @attributes ) . "]";
     } else {
         return "";