--- amavisd.original	2005-12-22 16:40:02.000000000 -0500
+++ amavisd	2005-12-29 11:42:50.000000000 -0500
@@ -3800,6 +3800,7 @@
 }
 
 use Errno qw(ENOENT EACCES);
+use File::Spec;
 use IO::File qw(O_CREAT O_EXCL O_WRONLY);
 use IO::Wrap;
 
@@ -3881,13 +3882,13 @@
            : $1 eq 'i' ? iso8601_timestamp($msginfo->rx_time,1,'-')
            : $1 eq 'n' ? am_id()
            : $1 eq '%' ? '%' : '%'.$1 }egs;
-        $mbxname = "$mbxname/$suggested_filename";
+        $mbxname = File::Spec->catfile($mbxname, $suggested_filename);
         if ($quarantine_subdir_levels>=1 && !$explicitly_suggested_filename) {
           # using a subdirectory structure to disperse quarantine files
           local($1,$2); my($subdir) = substr($msginfo->mail_id, 0, 1);
           $subdir=~/^[A-Z0-9]\z/i or die "Unexpected first char: $subdir";
           $mbxname =~ m{^ (.*/)? ([^/]+) \z}sx; my($path,$fname) = ($1,$2);
-          $mbxname = "$path$subdir/$fname";  # resulting full filename
+          $mbxname = File::Spec->catfile($path.$subdir, $fname);  # resulting full filename
           my($errn) = stat("$path$subdir") ? 0 : 0+$!;
           if ($errn == ENOENT) {  # check/prepare a set of subdirectories
             do_log(2, "checking/creating quarantine subdirs under $path");