diff --git a/core/composer.json b/core/composer.json
index eec2d4d..bbd6ef4 100644
--- a/core/composer.json
+++ b/core/composer.json
@@ -27,7 +27,7 @@
     "easyrdf/easyrdf": "0.9.*",
     "phpunit/phpunit": "4.6.*",
     "zendframework/zend-feed": "2.4.*",
-    "mikey179/vfsStream": "1.*",
+    "mikey179/vfsStream": "~1.2",
     "stack/builder": "1.0.*",
     "egulias/email-validator": "1.2.*",
     "behat/mink": "~1.6",
diff --git a/core/composer.lock b/core/composer.lock
index 7e43509..69c8f24 100644
--- a/core/composer.lock
+++ b/core/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "hash": "ed8b854299d501cf91b057146f2a5b2c",
+    "hash": "90d27e9e043ff2ad0966a80a49ef2823",
     "packages": [
         {
             "name": "behat/mink",