diff --git a/lib/Model/AbstractModel.php b/lib/Model/AbstractModel.php
index c7f367a..87bf2b3 100644
--- a/lib/Model/AbstractModel.php
+++ b/lib/Model/AbstractModel.php
@@ -86,7 +86,7 @@ abstract class AbstractModel
      * @param string $id
      * @throws Exception
      */
-    public function setId(string $id)
+    public function setId($id)
     {
         if (!self::isValidId($id)) {
             throw new Exception('Invalid paste ID.', 60);
@@ -154,7 +154,7 @@ abstract class AbstractModel
      * @param  string $id
      * @return bool
      */
-    public static function isValidId(string $id)
+    public static function isValidId($id)
     {
         return (bool) preg_match('#\A[a-f\d]{16}\z#', (string) $id);
     }
diff --git a/lib/Model/Paste.php b/lib/Model/Paste.php
index a665f50..dc9e9af 100644
--- a/lib/Model/Paste.php
+++ b/lib/Model/Paste.php
@@ -136,7 +136,7 @@ class Paste extends AbstractModel
      * @throws Exception
      * @return Comment
      */
-    public function getComment(string $parentId, string $commentId = '')
+    public function getComment($parentId, $commentId = '')
     {
         if (!$this->exists()) {
             throw new Exception('Invalid data.', 62);