diff --git a/.travis.yml b/.travis.yml
index bbf53ad..158714b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,8 +10,9 @@ php:
     - nightly
 env:
     matrix:
+        - COMPOSER_PREFER=""
         - COMPOSER_PREFER="--prefer-stable"
-        - COMPOSER_PREFER="--prefer-lowest"
+        - COMPOSER_PREFER="--prefer-lowest --prefer-stable"
 matrix:
     allow_failures:
         -
diff --git a/behat.yml b/behat.yml
index 965577b..e4b813f 100644
--- a/behat.yml
+++ b/behat.yml
@@ -5,7 +5,7 @@ default:
                 - FeatureContext
                 - Rezzza\RestApiBehatExtension\RestApiContext
                 - Rezzza\RestApiBehatExtension\Json\JsonContext:
-                    jsonSchemaBaseUrl: %paths.base%/features/bootstrap
+                    jsonSchemaBaseUrl: '%paths.base%/features/bootstrap'
 
     extensions:
         Rezzza\RestApiBehatExtension\Extension:
diff --git a/composer.json b/composer.json
index 64f80c6..e445fd1 100644
--- a/composer.json
+++ b/composer.json
@@ -15,11 +15,12 @@
     "autoload": {
         "psr-4": { "Rezzza\\RestApiBehatExtension\\": "src/" }
     },
+    "minimum-stability": "dev",
     "require": {
         "php": ">=5.6.0",
         "behat/behat": "~3.0",
         "atoum/atoum": "~1.0|~2.0|~3.0|3.0.x-dev",
-        "symfony/property-access": "~2.5|~3.0",
+        "symfony/property-access": "~2.5|~3.0|~4.0",
         "justinrainbow/json-schema": ">=3.0 <6.0",
         "psr/http-message": "^1.0",
         "php-http/discovery": "^1.0",
diff --git a/features/json_inspection_edge_case.feature b/features/json_inspection_edge_case.feature
index cdcf4b9..e30e8e8 100644
--- a/features/json_inspection_edge_case.feature
+++ b/features/json_inspection_edge_case.feature
@@ -12,7 +12,7 @@ Feature: Test json inspection edge cases
                     contexts:
                         - Rezzza\RestApiBehatExtension\RestApiContext
                         - Rezzza\RestApiBehatExtension\Json\JsonContext:
-                            jsonSchemaBaseUrl: %paths.base%/features/bootstrap
+                            jsonSchemaBaseUrl: '%paths.base%/features/bootstrap'
 
             extensions:
                 Rezzza\RestApiBehatExtension\Extension: