diff --git a/composer.json b/composer.json
index 48733ef..5a6c8e6 100644
--- a/composer.json
+++ b/composer.json
@@ -3,8 +3,8 @@
     "description": "Load guzzle service description from various file formats",
     "require": {
         "php": ">=5.5.0",
-        "symfony/config": "*",
-        "symfony/yaml": "*"
+        "symfony/config": "~3.0|^4.0",
+        "symfony/yaml": "~3.0|^4.0"
     },
     "license": "MIT",
     "authors": [