diff --git a/.dev-tools/generate-regex-format-referrers.php b/.dev-tools/generate-regex-format-referrers.php
index 258abc60e..51644610e 100755
--- a/.dev-tools/generate-regex-format-referrers.php
+++ b/.dev-tools/generate-regex-format-referrers.php
@@ -85,7 +85,7 @@ class Generator
     {
         foreach ($lines as $line) {
             //$data .= "\"~*\b" . preg_quote($line) . "\"\b" "\t1;\n";
-            $data .= '"' . '~*\\' . 'b' . preg_quote($line) . '\\' . "b\" \t1;\n";
+            $data .= '"' . '~*(?:\\' . 'b)' . preg_quote($line) . '(?:\\' . "b|)\" \t1;\n";
         }
         $this->writeToFile($file, $data);
     	}