diff --git a/.travis.yml b/.travis.yml
index b7e2ecaef..140a25e87 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,7 @@ php:
   - 7.3
   - 7.4
   - 8.0
+  - nightly
 
 sudo: false
 
diff --git a/composer.json b/composer.json
index 275036a28..ea2225439 100644
--- a/composer.json
+++ b/composer.json
@@ -15,8 +15,8 @@
         "php": "^7.1|^8.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "~9.2",
-        "mockery/mockery": "~1.4",
+        "phpunit/phpunit": "~8.0 | ~9.2",
+        "mockery/mockery": "~1.3",
         "guzzlehttp/guzzle": "~5.0"
     },
     "suggest": {