diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 87b9ce7cbc..2460aa8354 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -627,7 +627,7 @@ function add_query_arg() {
 	}
 	$ret = trim($ret, '?');
 	$ret = $protocol . $base . $ret . $frag;
-	$ret = trim($ret, '?');
+	$ret = rtrim($ret, '?');
 	return $ret;
 }