diff --git a/src/spec/Schema.php b/src/spec/Schema.php
index 59eb425c..b8c0709e 100644
--- a/src/spec/Schema.php
+++ b/src/spec/Schema.php
@@ -124,6 +124,10 @@ protected function attributeDefaults(): array
             'allOf' => null,
             'oneOf' => null,
             'anyOf' => null,
+            // nullable is only relevant, when a type is specified
+            // return null as default when there is no type
+            // return false as default when there is a type
+            'nullable' => $this->hasProperty('type') ? false : null,
         ];
     }
 
diff --git a/tests/spec/SchemaTest.php b/tests/spec/SchemaTest.php
index be53dd9b..0e19f74e 100644
--- a/tests/spec/SchemaTest.php
+++ b/tests/spec/SchemaTest.php
@@ -43,6 +43,29 @@ public function testRead()
         $this->assertFalse($schema->deprecated);
     }
 
+    public function testNullable()
+    {
+        /** @var $schema Schema */
+        $schema = Reader::readFromJson('{"type": "string"}', Schema::class);
+        $this->assertEquals(Type::STRING, $schema->type);
+        $this->assertFalse($schema->nullable);
+
+        /** @var $schema Schema */
+        $schema = Reader::readFromJson('{"type": "string", "nullable": false}', Schema::class);
+        $this->assertEquals(Type::STRING, $schema->type);
+        $this->assertFalse($schema->nullable);
+
+        /** @var $schema Schema */
+        $schema = Reader::readFromJson('{"type": "string", "nullable": true}', Schema::class);
+        $this->assertEquals(Type::STRING, $schema->type);
+        $this->assertTrue($schema->nullable);
+
+        // nullable is undefined if no type is given
+        $schema = Reader::readFromJson('{"oneOf": [{"type": "string"}, {"type": "integer"}]}', Schema::class);
+        $this->assertNull($schema->type);
+        $this->assertNull($schema->nullable);
+    }
+
     public function testReadObject()
     {
         /** @var $schema Schema */