diff --git a/.travis.yml b/.travis.yml
index 41a90bc..b9cca37 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -27,4 +27,4 @@ before_script:
 
 
 script:
-  - phpunit --verbose $PHPUNIT_FLAGS
+  - ./vendor/bin/phpunit --verbose $PHPUNIT_FLAGS
diff --git a/composer.json b/composer.json
index 3f92972..e17d7e2 100644
--- a/composer.json
+++ b/composer.json
@@ -21,6 +21,9 @@
         "yiisoft/yii2": ">=2.0.4",
         "swiftmailer/swiftmailer": "~6.0"
     },
+    "require-dev": {
+        "phpunit/phpunit": "<7"
+    },
     "repositories": [
         {
             "type": "composer",