diff --git a/file/lib/form/ChatForm.class.php b/file/lib/form/ChatForm.class.php
index 9e7b129..4a8ec7e 100644
--- a/file/lib/form/ChatForm.class.php
+++ b/file/lib/form/ChatForm.class.php
@@ -54,9 +54,14 @@ public function readFormParameters() {
 	 */
 	public function validate() {
 		parent::validate();
+		
 		if ($this->message === '') {
 			throw new UserInputException('text');
 		}
+		
+		if (strlen($this->message) > CHAT_MAX_LENGTH) {
+			throw new UserInputException('text', 'tooLong');
+		}
 	}
 	
 	/**