diff --git a/composer.json b/composer.json
index 3c69df0..f8b9d0f 100644
--- a/composer.json
+++ b/composer.json
@@ -22,7 +22,7 @@
   },
   "require": {
     "php": ">=7",
-    "symfony/symfony": "2.3.*|2.7.*|2.8.*"
+    "symfony/symfony": "^2.7|^3.3"
   },
   "suggests": {
     "phpseclib/phpseclib": "^2.0",