diff --git a/src/Traits/MappableTrait.php b/src/Traits/MappableTrait.php
index e25d4d8..951f504 100644
--- a/src/Traits/MappableTrait.php
+++ b/src/Traits/MappableTrait.php
@@ -37,7 +37,7 @@ public function mapFromArray(array $data) {
 	 * @throws \InvalidArgumentException
 	 * @throws ModelMapperException
 	 */
-	public function mapFromJson(string $data) {
+	public function mapFromJson($data) {
 		$object = json_decode($data);
         if($object === null) {
             throw new \InvalidArgumentException('Invalid json supplied.');
@@ -57,7 +57,7 @@ public function mapFromObject($object) {
     /**
      * @param string $xml
      */
-    public function mapFromXml(string $xml) {
+    public function mapFromXml($xml) {
         $mapper = new XmlModelMapper();
         $mapper->map($xml, $this);
     }
diff --git a/src/Traits/ValidatableTrait.php b/src/Traits/ValidatableTrait.php
index e1d1c4e..f1642d7 100644
--- a/src/Traits/ValidatableTrait.php
+++ b/src/Traits/ValidatableTrait.php
@@ -15,7 +15,7 @@ trait ValidatableTrait {
 	/**
 	 * @param string $validationType
 	 */
-	public function validate(string $validationType = '') {
+	public function validate($validationType = '') {
 		$validator = new ModelValidator();
 		$validator->validate($this, $validationType);
 	}