diff --git a/migrateSessions.php b/migrateSessions.php
index f77d798..c5f4137 100644
--- a/migrateSessions.php
+++ b/migrateSessions.php
@@ -63,8 +63,8 @@
   if ( ! is_readable($file)) {
     die("Could not read $file. Please run the script as root or as the web server user.\n");
   }
-  if ( ! preg_match('/^sess_(\w+)$/', $sessionFile, $matches)) {
-    die("Session file name does not match expected pattern (sess_\\w+): $sessionFile\n");
+  if ( ! preg_match('/^sess_([a-zA-Z0-9,-]+)$/', $sessionFile, $matches)) {
+    die("Session file name does not match expected pattern (sess_[a-zA-Z0-9,-]+): $sessionFile\n");
   }
   $sessionId = $matches[1];
   $i++;