1 files changed, 3 insertions, 0 deletions
diff --git a/composer.json b/composer.json
index 7cf1750..2fc4809 100644
--- a/composer.json
+++ b/composer.json
@@ -8,6 +8,9 @@
     "require": {
         "php": ">=5.4.0"
     },
+    "require-dev": {
+        "phpunit/phpunit": "~4.8"
+    },
     "autoload": {
         "psr-4": {
             "React\\Promise\\": "src/"