--- XHProfRunsFile.orig	2011-12-19 13:32:42.000000000 -0500
+++ XHProfRunsFile.inc	2011-12-19 13:35:39.000000000 -0500
@@ -17,11 +17,11 @@ class XHProfRunsFile implements XHProfRu
     return uniqid();
   }
 
   private function file_name($run_id, $type) {
 
-    $file = "$run_id.$type." . $this->suffix;
+    $file = "$run_id." . str_replace('/', '-', $type) . '.' . $this->suffix;
 
     if (!empty($this->dir)) {
       $file = $this->dir . "/" . $file;
     }
     return $file;