diff --git a/src/Drivers/EloquentEntitySet.php b/src/Drivers/EloquentEntitySet.php
index 4f4dd73b6..e75afbe78 100644
--- a/src/Drivers/EloquentEntitySet.php
+++ b/src/Drivers/EloquentEntitySet.php
@@ -187,7 +187,7 @@ public function read(PropertyValue $key): Entity
      */
     protected function setModelAttributes(Model $model, PropertyValues $propertyValues): Model
     {
-        return $propertyValues->getDeclaredPropertyValues()->reduce(function(Model $model, PropertyValue $value) {
+        return $propertyValues->getDeclaredPropertyValues()->reduce(function (Model $model, PropertyValue $value) {
             return $model->setAttribute(
                 $this->getPropertySourceName($value->getProperty()),
                 $value->getPrimitive()->toMixed(),
diff --git a/src/Helper/ObjectArray.php b/src/Helper/ObjectArray.php
index ac36ded28..15eb4ab5f 100644
--- a/src/Helper/ObjectArray.php
+++ b/src/Helper/ObjectArray.php
@@ -303,6 +303,7 @@ public function map(callable $callback)
     }
 
     /**
+     * Reduce the objects in the array
      * @param  callable(mixed $initial, mixed $value, mixed $key): mixed  $callback
      * @param $initial
      * @return mixed|null
diff --git a/src/PathSegment/OpenAPI.php b/src/PathSegment/OpenAPI.php
index c9596f967..0e0a7d968 100644
--- a/src/PathSegment/OpenAPI.php
+++ b/src/PathSegment/OpenAPI.php
@@ -1105,7 +1105,7 @@ public static function applyProperty(?Property $property = null, array $schema =
         $schema['nullable'] = $property->isNullable();
 
         if ($property->hasStaticDefaultValue()) {
-            $schema['default'] = $property->computeDefaultValue();
+            $schema['default'] = $property->computeDefaultValue()->toJson();
         }
 
         if ($property->hasMaxLength()) {
diff --git a/src/Primitive.php b/src/Primitive.php
index fa03e9c84..50e6f9b84 100644
--- a/src/Primitive.php
+++ b/src/Primitive.php
@@ -18,6 +18,7 @@
 use Flat3\Lodata\Interfaces\ResponseInterface;
 use Flat3\Lodata\Interfaces\SerializeInterface;
 use Flat3\Lodata\Traits\HasIdentifier;
+use Stringable;
 
 /**
  * Primitive
@@ -57,7 +58,12 @@ public function __construct($value = null)
      * @return Primitive
      */
     abstract public function set($value);
-    
+
+    /**
+     * Test the provided value is formatted correctly for this type
+     * @param $value
+     * @return bool
+     */
     public function allows($value): bool
     {
         return true;
@@ -186,7 +192,7 @@ public function matches($value): bool
             $value = $value->get();
         }
 
-        if (is_scalar($value) || is_null($value) || $value instanceof \Stringable) {
+        if (is_scalar($value) || is_null($value) || $value instanceof Stringable) {
             return (string) $this->get() === (string) $value;
         }
 
diff --git a/src/PrimitiveType.php b/src/PrimitiveType.php
index ad026ee8c..2f833dcc2 100644
--- a/src/PrimitiveType.php
+++ b/src/PrimitiveType.php
@@ -100,6 +100,11 @@ public function getOpenAPISchema(): array
         return $this->instance()->getOpenAPISchema();
     }
 
+    /**
+     * Test the provided value is correctly formatted for this type
+     * @param $value
+     * @return bool
+     */
     public function allowsValue($value): bool
     {
         return $this->instance()->allows($value);
diff --git a/src/Type.php b/src/Type.php
index 9bfb1c88e..8e63f8d81 100644
--- a/src/Type.php
+++ b/src/Type.php
@@ -230,6 +230,11 @@ public function is(string $class): bool
         return is_a($this->factory, $class, true);
     }
 
+    /**
+     * Test the provided value is correctly formatted for this type
+     * @param $value
+     * @return bool
+     */
     public function allowsValue($value): bool
     {
         return true;
diff --git a/src/Type/Guid.php b/src/Type/Guid.php
index e4677254c..1ddc1a7d1 100644
--- a/src/Type/Guid.php
+++ b/src/Type/Guid.php
@@ -9,6 +9,7 @@
 use Flat3\Lodata\PathSegment\OpenAPI;
 use Flat3\Lodata\Primitive;
 use Flat3\Lodata\Property;
+use Stringable;
 
 /**
  * Guid
@@ -27,7 +28,7 @@ public function matches($value): bool
             $value = $value->get();
         }
 
-        if (is_scalar($value) || is_null($value) || $value instanceof \Stringable) {
+        if (is_scalar($value) || is_null($value) || $value instanceof Stringable) {
             return (string) $this->get() === strtoupper((string) $value);
         }
 
diff --git a/tests/Queries/GuidTest.php b/tests/Queries/GuidTest.php
index da2ab7896..e5ecc07d7 100644
--- a/tests/Queries/GuidTest.php
+++ b/tests/Queries/GuidTest.php
@@ -53,5 +53,14 @@ public function test_filter_guid()
             (new Request)
                 ->path('/examples(00000000-0000-0000-0000-0012ea25eefb)')
         );
+
+        $this->assertBadRequest(
+            (new Request)
+                ->path('/examples')
+                ->body([
+                    'id' => 'hello',
+                ])
+                ->post(),
+        );
     }
 }
diff --git a/tests/__snapshots__/Queries/DefaultValueTest__test_default__4.json b/tests/__snapshots__/Queries/DefaultValueTest__test_default__4.json
index 360dfe6b1..3154c9c27 100644
--- a/tests/__snapshots__/Queries/DefaultValueTest__test_default__4.json
+++ b/tests/__snapshots__/Queries/DefaultValueTest__test_default__4.json
@@ -245,7 +245,7 @@
                     "a": {
                         "type": "string",
                         "nullable": false,
-                        "default": {}
+                        "default": "a"
                     },
                     "b": {
                         "type": "string",
@@ -260,7 +260,7 @@
                     "a": {
                         "type": "string",
                         "nullable": false,
-                        "default": {}
+                        "default": "a"
                     },
                     "b": {
                         "type": "string",
diff --git a/tests/__snapshots__/Queries/GuidTest__test_filter_guid__6.json b/tests/__snapshots__/Queries/GuidTest__test_filter_guid__6.json
new file mode 100644
index 000000000..e60f45fc2
--- /dev/null
+++ b/tests/__snapshots__/Queries/GuidTest__test_filter_guid__6.json
@@ -0,0 +1,9 @@
+{
+    "error": {
+        "code": "property_value_invalid",
+        "message": "The value property 'id' is not valid",
+        "target": null,
+        "details": [],
+        "innererror": {}
+    }
+}