diff --git a/classes/class_text.php b/classes/class_text.php
index f377d5e1..a3a13ea5 100644
--- a/classes/class_text.php
+++ b/classes/class_text.php
@@ -115,9 +115,9 @@ function valid_url($Str, $Extension = '', $Inline = false) {
 
 		// query string
 		if ($Inline) {
-			$Regex .= '(\?([0-9a-z\-_.,%\/\@~&=:;()+*\^$!#|]|\[\d*\])*)?';
+			$Regex .= '(\?([0-9a-z\-_.,%\/\@~&=:;()+*\^$!#|?]|\[\d*\])*)?';
 		} else {
-			$Regex .= '(\?[0-9a-z\-_.,%\/\@[\]~&=:;()+*\^$!#|]*)?';
+			$Regex .= '(\?[0-9a-z\-_.,%\/\@[\]~&=:;()+*\^$!#|?]*)?';
 		}
 
 		$Regex .= '(#[a-z0-9\-_.,%\/\@[\]~&=:;()+*\^$!]*)?'; // #anchor