diff --git a/res/composer-schema.json b/res/composer-schema.json
index 80ce27718..a9a5df2b4 100644
--- a/res/composer-schema.json
+++ b/res/composer-schema.json
@@ -442,6 +442,10 @@
             "items": {
                 "type": "string"
             }
+        },
+        "abandoned": {
+            "type": ["boolean"],
+            "description": "Indicates whether this package has been abandoned. Defaults to false."
         }
     }
 }
diff --git a/tests/Composer/Test/Json/ComposerSchemaTest.php b/tests/Composer/Test/Json/ComposerSchemaTest.php
index 51949797c..14521faae 100644
--- a/tests/Composer/Test/Json/ComposerSchemaTest.php
+++ b/tests/Composer/Test/Json/ComposerSchemaTest.php
@@ -38,6 +38,12 @@ class ComposerSchemaTest extends \PHPUnit_Framework_TestCase
         ), $this->check($json));
     }
 
+    public function testOptionalAbandonedProperty()
+    {
+        $json = '{"name": "name", "description": "description", "abandoned": true}';
+        $this->assertTrue($this->check($json));
+    }
+
     public function testMinimumStabilityValues()
     {
         $json = '{ "name": "vendor/package", "description": "generic description", "minimum-stability": "" }';