diff --git a/Models/Address.php b/Models/Address.php
index 21fd5a7..2a8d0ce 100755
--- a/Models/Address.php
+++ b/Models/Address.php
@@ -58,7 +58,7 @@ class Address extends Location
     /**
      * {@inheritdoc}
      */
-    public function jsonSerialize()
+    public function jsonSerialize() : mixed
     {
         return $this->toArray();
     }
diff --git a/Models/Module.php b/Models/Module.php
index 20aedc1..55235db 100755
--- a/Models/Module.php
+++ b/Models/Module.php
@@ -150,7 +150,7 @@ class Module
     /**
      * {@inheritdoc}
      */
-    public function jsonSerialize()
+    public function jsonSerialize() : mixed
     {
         return $this->toArray();
     }