Add config.platform to the list of locked properties

composer.lock

@@ -5,6 +5,7 @@
         "This file is @generated automatically"
     ],
     "hash": "3024e89a7e808b8dece156112459a7ea",
+    "content-hash": "01608741fe66bb9528d7c77c0a422965",
     "packages": [
         {
             "name": "composer/spdx-licenses",

src/Composer/Package/Locker.php

@@ -397,6 +397,8 @@ class Locker
         $content = json_decode($composerFileContents, true);
 
         $relevantKeys = array(
+            'name',
+            'version',
             'require',
             'require-dev',
             'conflict',
@@ -406,8 +408,6 @@ class Locker
             'prefer-stable',
             'repositories',
             'extra',
-            'version',
-            'name',
         );
 
         $relevantContent = array();
@@ -415,6 +415,9 @@ class Locker
         foreach (array_intersect($relevantKeys, array_keys($content)) as $key) {
             $relevantContent[$key] = $content[$key];
         }
+        if (isset($content['config']['platform'])) {
+            $relevantContent['config']['platform'] = $content['config']['platform'];
+        }
 
         ksort($relevantContent);
         return md5(json_encode($relevantContent));