diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index e20929f..4a39a96 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php: [ '7.1', '7.2', '7.3', '7.4', '8.0' ]
+        php: [ '7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3', '8.4' ]
 
     steps:
       - uses: actions/checkout@master
diff --git a/.gitignore b/.gitignore
index 3a9875b..6ee3b99 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 /vendor/
 composer.lock
+composer.phar
\ No newline at end of file
diff --git a/Makefile b/Makefile
index 3ab49c0..4f33df0 100644
--- a/Makefile
+++ b/Makefile
@@ -3,6 +3,12 @@
 tests: vendor
 	php -d zend.assertions=1 -d assert.exception=1 vendor/bin/peridot ./specs
 
-vendor: composer.json composer.lock
-	composer install
+vendor: composer.json composer.phar
+	php composer.phar install
 	touch vendor
+
+composer.phar:
+	php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
+	php -r "if (hash_file('sha384', 'composer-setup.php') === 'dac665fdc30fdd8ec78b38b9800061b4150413ff2e3b6f88543c636f7cd84f6db9189d43a81e5503cda447da73c7e5b6') { echo 'Installer verified'.PHP_EOL; } else { echo 'Installer corrupt'.PHP_EOL; unlink('composer-setup.php'); exit(1); }"
+	php composer-setup.php
+	php -r "unlink('composer-setup.php');"
\ No newline at end of file
diff --git a/composer.json b/composer.json
index 9706fc9..a9b48c1 100644
--- a/composer.json
+++ b/composer.json
@@ -9,8 +9,8 @@
         "auto-wiring"
     ],
     "require": {
-        "php": ">=7.1",
-        "psr/container": "^1.0",
+        "php": "^7.1|^8.0",
+        "psr/container": "^1.0|^2.0",
         "technically/null-container": "^1.0",
         "technically/callable-reflection": "^0.4.0"
     },