diff --git a/build/build_helper.php b/build/build_helper.php
index 94fc0ff3b5..2d9b86b3c3 100644
--- a/build/build_helper.php
+++ b/build/build_helper.php
@@ -177,7 +177,7 @@ class build_package
 			}
 
 			// Is binary?
-			if (preg_match('/^Binary files ' . $package_name . '\/(.*) and [a-z0-9_-]+\/\1 differ/i', $line, $match))
+			if (preg_match('/^Binary files ' . $package_name . '\/(.*) and [a-z0-9._-]+\/\1 differ/i', $line, $match))
 			{
 				$binary[] = trim($match[1]);
 			}