exact length passed as string needs to be casted to int
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index 6cbe032..069751b 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -1035,7 +1035,7 @@
 	 * Exact Length
 	 *
 	 * @param	string
-	 * @param	int
+	 * @param	string
 	 * @return	bool
 	 */
 	public function exact_length($str, $val)
@@ -1045,6 +1045,8 @@
 			return FALSE;
 		}
 
+		$val = (int) $val;
+
 		return (MB_ENABLED === TRUE)
 			? (mb_strlen($str) === $val)
 			: (strlen($str) === $val);