diff --git a/phpBB/includes/captcha/plugins/captcha_abstract.php b/phpBB/includes/captcha/plugins/captcha_abstract.php
index c6de2ff887..86ecdaf97e 100644
--- a/phpBB/includes/captcha/plugins/captcha_abstract.php
+++ b/phpBB/includes/captcha/plugins/captcha_abstract.php
@@ -178,7 +178,7 @@ class phpbb_default_captcha
 		return;
 	}
 
-	function validate()
+	function validate($data = false)
 	{
 		global $config, $db, $user;
 		
@@ -344,7 +344,7 @@ class phpbb_default_captcha
 	
 	function is_solved()
 	{
-		if ($this->solved === 0)
+		if (request_var('confirm_code', false) && $this->solved === 0)
 		{
 			$this->validate();
 		}
diff --git a/phpBB/includes/ucp/ucp_register.php b/phpBB/includes/ucp/ucp_register.php
index a802a35b87..da62061a72 100644
--- a/phpBB/includes/ucp/ucp_register.php
+++ b/phpBB/includes/ucp/ucp_register.php
@@ -222,8 +222,8 @@ class ucp_register
 
 			if ($config['enable_confirm'])
 			{
-				$vc_response = $captcha->validate();
-				if (!$captcha->is_solved() && $vc_response)
+				$vc_response = $captcha->validate($data);
+				if ($vc_response)
 				{
 					$error[] = $vc_response;
 				}
diff --git a/phpBB/posting.php b/phpBB/posting.php
index 9d06ac3e2c..598f500bc4 100644
--- a/phpBB/posting.php
+++ b/phpBB/posting.php
@@ -772,7 +772,12 @@ if ($submit || $preview || $refresh)
 
 	if ($config['enable_post_confirm'] && !$user->data['is_registered'] && in_array($mode, array('quote', 'post', 'reply')))
 	{
-		$vc_response = $captcha->validate();
+		$captcha_data = array(
+			'message'	=> utf8_normalize_nfc(request_var('message', '', true)),
+			'subject'	=> utf8_normalize_nfc(request_var('subject', '', true)),
+			'username'	=> utf8_normalize_nfc(request_var('username', '', true)),
+		);
+		$vc_response = $captcha->validate($captcha_data);
 		if ($vc_response)
 		{
 			$error[] = $vc_response;