diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index d0cc5ee..61e70df 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       matrix:
         operating-system: [ubuntu-latest]
-        php-versions: ['7.2', '7.3', '7.4']
+        php-versions: ['7.2', '7.3', '7.4', '8.0']
     name: PHP ${{ matrix.php-versions }} Test on ${{ matrix.operating-system }}
 
     steps:
diff --git a/composer.json b/composer.json
index e519fd8..653d2b2 100644
--- a/composer.json
+++ b/composer.json
@@ -10,12 +10,12 @@
     "homepage": "https://github.com/selective-php/image-type",
     "license": "MIT",
     "require": {
-        "php": "^7.2"
+        "php": "^7.2 || ^8.0"
     },
     "require-dev": {
         "overtrue/phplint": "^1.1",
         "phpunit/phpunit": "^8",
-        "phpstan/phpstan-shim": "^0.11",
+        "phpstan/phpstan": "^0.12",
         "squizlabs/php_codesniffer": "^3.4"
     },
     "scripts": {
diff --git a/tests/ImageTypeDetectorTest.php b/tests/ImageTypeDetectorTest.php
index 92e9c8c..d4d8c2d 100644
--- a/tests/ImageTypeDetectorTest.php
+++ b/tests/ImageTypeDetectorTest.php
@@ -66,7 +66,7 @@ public function testGetImageTypeFromFile(string $file, string $format, string $m
     /**
      * Provider.
      *
-     * @return array
+     * @return array<int, array<int, string>>
      */
     public function providerGetImageTypeFromFile(): array
     {