diff --git a/composer.lock b/composer.lock
index cea0492..e2c3ed6 100644
--- a/composer.lock
+++ b/composer.lock
@@ -67,16 +67,16 @@
         },
         {
             "name": "composer/composer",
-            "version": "1.5.2",
+            "version": "1.5.6",
             "source": {
                 "type": "git",
                 "url": "https://github.com/composer/composer.git",
-                "reference": "c639623fa2178b404ed4bab80f0d1263853fa4ae"
+                "reference": "4f7f9c12753ec43f1e4629e2a71cabe81f2a4eab"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/composer/composer/zipball/c639623fa2178b404ed4bab80f0d1263853fa4ae",
-                "reference": "c639623fa2178b404ed4bab80f0d1263853fa4ae",
+                "url": "https://api.github.com/repos/composer/composer/zipball/4f7f9c12753ec43f1e4629e2a71cabe81f2a4eab",
+                "reference": "4f7f9c12753ec43f1e4629e2a71cabe81f2a4eab",
                 "shasum": ""
             },
             "require": {
@@ -140,7 +140,7 @@
                 "dependency",
                 "package"
             ],
-            "time": "2017-09-11T14:59:26+00:00"
+            "time": "2017-12-18T11:09:18+00:00"
         },
         {
             "name": "composer/semver",