diff --git a/src/Argument/ArgumentSet.php b/src/Argument/ArgumentSet.php
index 6e3cec618..b675a51a2 100644
--- a/src/Argument/ArgumentSet.php
+++ b/src/Argument/ArgumentSet.php
@@ -10,7 +10,7 @@ final class ArgumentSet extends \Infinityloop\Utils\ObjectSet implements \Graphp
 
     private array $defaults = [];
 
-    public function getDefaults() : array
+    public function getRawDefaults() : array
     {
         return $this->defaults;
     }
@@ -30,7 +30,7 @@ protected function getKey(object $object) : string
         $defaultValue = $object->getDefaultValue();
 
         if ($defaultValue instanceof \Graphpinator\Resolver\Value\ValidatedValue) {
-            $this->defaults[$object->getName()] = $defaultValue;
+            $this->defaults[$object->getName()] = $defaultValue->getRawValue();
         }
 
         return $object->getName();
diff --git a/src/Type/InputType.php b/src/Type/InputType.php
index b08846c1c..a986979fa 100644
--- a/src/Type/InputType.php
+++ b/src/Type/InputType.php
@@ -21,7 +21,7 @@ final public function applyDefaults($value) : \stdClass
             throw new \Exception('Composite input type without fields specified.');
         }
 
-        return self::merge($value, $this->getArguments()->getDefaults());
+        return self::merge($value, (object) $this->getArguments()->getRawDefaults());
     }
 
     final public function getArguments() : \Graphpinator\Argument\ArgumentSet
@@ -48,12 +48,13 @@ final public function printSchema() : string
 
     abstract protected function getFieldDefinition() : \Graphpinator\Argument\ArgumentSet;
 
-    private static function merge(\stdClass $core, iterable $supplement) : \stdClass
+    private static function merge(\stdClass $core, \stdClass $supplement) : \stdClass
     {
         foreach ($supplement as $key => $value) {
             if (\property_exists($core, $key)) {
-                if ($core->{$key} instanceof \stdClass) {
-                    $core->{$key} = self::merge($core->{$key}, $supplement[$key]);
+                if ($core->{$key} instanceof \stdClass &&
+                    $supplement->{$key} instanceof \stdClass) {
+                    $core->{$key} = self::merge($core->{$key}, $supplement->{$key});
                 }
 
                 continue;