2 files changed, 2 insertions, 2 deletions

diff --git a/.travis.yml b/.travis.yml
index fb95235c..afccce08 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -43,7 +43,7 @@ cache:
 
 install:
   # install/update composer and php dependencies
-  - composer install --prefer-dist
+  - composer update --ignore-platform-reqs
 
 before_script:
   - PATH=${PATH//:\.\/node_modules\/\.bin/}
diff --git a/composer.json b/composer.json
index 738d9f58..35043fd2 100644
--- a/composer.json
+++ b/composer.json
@@ -28,7 +28,7 @@
     "require-dev": {
         "roave/security-advisories": "dev-master",
         "phpunit/phpcov": "*",
-        "phpunit/phpunit": "^7.5",
+        "phpunit/phpunit": "^7.5 || ^8.0 || ^9.0",
         "squizlabs/php_codesniffer": "3.*"
     },
     "suggest": {