diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
index 8f525a97f..7f161bd79 100644
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -41,7 +41,7 @@ To achieve this, you need to acquire the Composer source code:
 2. Download the [`composer.phar`](https://getcomposer.org/composer.phar) executable
 3. Run Composer to get the dependencies: `cd composer && php ../composer.phar install`
 
-You can run the test suite by executing `vendor/bin/phpunit` when inside the
+You can run the test suite by executing `vendor/bin/simple-phpunit` when inside the
 composer directory, and run Composer by executing the `bin/composer`. To test
 your modified Composer code against another project, run `php
 /path/to/composer/bin/composer` inside that project's directory.
diff --git a/res/composer-schema.json b/res/composer-schema.json
index 7aa8fbd1a..c5e3376ee 100644
--- a/res/composer-schema.json
+++ b/res/composer-schema.json
@@ -1,6 +1,6 @@
 {
     "$schema": "https://json-schema.org/draft-04/schema#",
-    "name": "Package",
+    "title": "Package",
     "type": "object",
     "additionalProperties": false,
     "required": [ "name", "description" ],
@@ -42,7 +42,7 @@
         "version": {
             "type": "string",
             "description": "Package version, see https://getcomposer.org/doc/04-schema.md#version for more info on valid schemes.",
-            "pattern": "^v?\\d+(((\\.\\d+)?\\.\\d+)?\\.\\d+)?|^dev-"
+            "pattern": "^v?\\d+(\\.\\d+){0,3}|^dev-"
         },
         "time": {
             "type": "string",
@@ -397,7 +397,7 @@
         "minimum-stability": {
             "type": ["string"],
             "description": "The minimum stability the packages must have to be install-able. Possible values are: dev, alpha, beta, RC, stable.",
-            "pattern": "^dev|alpha|beta|rc|RC|stable$"
+            "enum": ["dev", "alpha", "beta", "rc", "RC", "stable"]
         },
         "prefer-stable": {
             "type": ["boolean"],
diff --git a/tests/Composer/Test/Json/ComposerSchemaTest.php b/tests/Composer/Test/Json/ComposerSchemaTest.php
index 687c1137a..0eece664c 100644
--- a/tests/Composer/Test/Json/ComposerSchemaTest.php
+++ b/tests/Composer/Test/Json/ComposerSchemaTest.php
@@ -71,25 +71,23 @@ class ComposerSchemaTest extends TestCase
 
     public function testMinimumStabilityValues()
     {
-        $json = '{ "name": "vendor/package", "description": "generic description", "minimum-stability": "" }';
-        $this->assertEquals(array(
+        $expectedError = array(
             array(
                 'property' => 'minimum-stability',
-                'message' => 'Does not match the regex pattern ^dev|alpha|beta|rc|RC|stable$',
-                'constraint' => 'pattern',
-                'pattern' => '^dev|alpha|beta|rc|RC|stable$',
+                'message' => 'Does not have a value in the enumeration ["dev","alpha","beta","rc","RC","stable"]',
+                'constraint' => 'enum',
+                'enum' => array('dev', 'alpha', 'beta', 'rc', 'RC', 'stable'),
             ),
-        ), $this->check($json), 'empty string');
+        );
+
+        $json = '{ "name": "vendor/package", "description": "generic description", "minimum-stability": "" }';
+        $this->assertEquals($expectedError, $this->check($json), 'empty string');
 
         $json = '{ "name": "vendor/package", "description": "generic description", "minimum-stability": "dummy" }';
-        $this->assertEquals(array(
-            array(
-                'property' => 'minimum-stability',
-                'message' => 'Does not match the regex pattern ^dev|alpha|beta|rc|RC|stable$',
-                'constraint' => 'pattern',
-                'pattern' => '^dev|alpha|beta|rc|RC|stable$',
-            ),
-        ), $this->check($json), 'dummy');
+        $this->assertEquals($expectedError, $this->check($json), 'dummy');
+
+        $json = '{ "name": "vendor/package", "description": "generic description", "minimum-stability": "devz" }';
+        $this->assertEquals($expectedError, $this->check($json), 'devz');
 
         $json = '{ "name": "vendor/package", "description": "generic description", "minimum-stability": "dev" }';
         $this->assertTrue($this->check($json), 'dev');