diff --git a/.travis.yml b/.travis.yml
index 1639035..788e635 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,7 @@ php:
   - 5.6
   - 7.0
   - 7.1
+  - 7.2
 
 env:
   global:
diff --git a/composer.json b/composer.json
index 51001b5..ac7fc01 100644
--- a/composer.json
+++ b/composer.json
@@ -15,7 +15,7 @@
         "php-http/client-common": "^1.1",
         "php-http/message": "^1.0",
         "guzzlehttp/psr7": "^1.2",
-        "symfony/yaml": "^3.2"
+        "symfony/yaml": "^3.2||^4.0"
     },
     "require-dev": {
         "symfony/debug": "*",