diff --git a/phpBB/includes/functions_post.php b/phpBB/includes/functions_post.php
index a73ea20fa7..077da90cb6 100644
--- a/phpBB/includes/functions_post.php
+++ b/phpBB/includes/functions_post.php
@@ -65,6 +65,7 @@ function prepare_message($message, $html_on, $bbcode_on, $smile_on, $bbcode_uid
 		}
 
 		$message = addslashes($message);
+		$message = str_replace('"', '\"', $message);
 	}
 	else
 	{