diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 61911f4..43a2850 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -35,6 +35,18 @@ jobs:
           - php-version: '7.4'
             SYMFONY_PHPUNIT_VERSION: 8.5.49
             integration: true
+          - php-version: '8.0'
+            SYMFONY_PHPUNIT_VERSION: 9.6.31
+          - php-version: '8.1'
+            SYMFONY_PHPUNIT_VERSION: 9.6.31
+          - php-version: '8.2'
+            SYMFONY_PHPUNIT_VERSION: 9.6.31
+          - php-version: '8.3'
+            SYMFONY_PHPUNIT_VERSION: 9.6.31
+          - php-version: '8.4'
+            SYMFONY_PHPUNIT_VERSION: 9.6.31
+          - php-version: '8.5'
+            SYMFONY_PHPUNIT_VERSION: 9.6.31
     env:
       ESIA_LOGIN_ATTEMPTS: 3
       SYMFONY_PHPUNIT_VERSION: ${{ matrix.SYMFONY_PHPUNIT_VERSION }}
diff --git a/composer.json b/composer.json
index 808aecc..b1b21dd 100644
--- a/composer.json
+++ b/composer.json
@@ -16,7 +16,7 @@
     }
   ],
   "require": {
-    "php": "^5.6 || ^7.0",
+    "php": "^5.6 || ^7.0 || ^8.0",
     "lcobucci/jwt": "^3.2.2",
     "league/oauth2-client": "^2.7.0",
     "psr/log": "^1.0",
diff --git a/src/Security/Signer/OpensslPkcs7.php b/src/Security/Signer/OpensslPkcs7.php
index 85a082b..df3ece6 100644
--- a/src/Security/Signer/OpensslPkcs7.php
+++ b/src/Security/Signer/OpensslPkcs7.php
@@ -22,7 +22,7 @@ public function sign($message)
         }
 
         $privateKey = openssl_pkey_get_private($keyContent, $this->privateKeyPassword);
-        if (!is_resource($privateKey)) {
+        if (false === $privateKey) {
             throw SignException::canNotReadPrivateKey($this->privateKeyPath);
         }