diff --git a/fp-includes/core/core.static.php b/fp-includes/core/core.static.php
index 6a6a769..4824963 100755
--- a/fp-includes/core/core.static.php
+++ b/fp-includes/core/core.static.php
@@ -34,7 +34,7 @@
 	}
 	
 	function static_isvalid($id) {
-		return !preg_match('[^./\\\\]+');
+		return !preg_match('[^./\\\\]+', $id);
 	}