diff --git a/phpBB/includes/bbcode.php b/phpBB/includes/bbcode.php
index 1f4567f1e8..0651eeadf2 100644
--- a/phpBB/includes/bbcode.php
+++ b/phpBB/includes/bbcode.php
@@ -176,7 +176,7 @@ class bbcode
 							'[/quote:$uid]'	=> $this->bbcode_tpl('quote_close', $bbcode_id)
 						),
 						'preg' => array(
-							'#\[quote(?:="(.*?)")?:$uid\]((?!\[quote(?:="(.*?)")?:$uid\]).)?#ise'	=> "\$this->bbcode_second_pass_quote('\$1', '\$2')"
+							'#\[quote(?:="(.*?)")?:$uid\]((?!\[quote(?:=".*?")?:$uid\]).)?#ise'	=> "\$this->bbcode_second_pass_quote('\$1', '\$2')"
 						)
 					);
 				break;