diff --git a/composer.json b/composer.json
index 3bd5e20..0bcf980 100644
--- a/composer.json
+++ b/composer.json
@@ -48,7 +48,8 @@
         "simplesamlphp/simplesamlphp": "^2.2",
         "simplesamlphp/simplesamlphp-module-ldap": "^2.2",
         "symfony/http-foundation": "^6.4",
-        "symfony/ldap": "^6.4"
+        "symfony/ldap": "^6.4",
+        "symfony/security-core": "^6.4"
     },
     "require-dev": {
         "simplesamlphp/simplesamlphp-test-framework": "^1.6.0"
diff --git a/src/Auth/Source/X509userCert.php b/src/Auth/Source/X509userCert.php
index 256d58f..aaa56b0 100644
--- a/src/Auth/Source/X509userCert.php
+++ b/src/Auth/Source/X509userCert.php
@@ -15,6 +15,7 @@
 use SimpleSAML\Utils;
 use SimpleSAML\XHTML\Template;
 use Symfony\Component\Ldap\Entry;
+use Symfony\Component\Ldap\Ldap;
 use Symfony\Component\Ldap\Security\LdapUserProvider;
 use Symfony\Component\Security\Core\Exception\UserNotFoundException;
 
@@ -279,9 +280,10 @@ public function findUserByAttribute(string $attr, string $value): ?Entry
         Assert::nullOrnotWhitespaceOnly($searchPassword);
 
         $ldap = ConnectorFactory::fromAuthSource($this->backend);
+        $connection = new Ldap($ldap->getAdapter());
 
         foreach ($searchBase as $base) {
-            $ldapUserProvider = new LdapUserProvider($ldap, $base, $searchUsername, $searchPassword, [], $attr);
+            $ldapUserProvider = new LdapUserProvider($connection, $base, $searchUsername, $searchPassword, [], $attr);
             try {
                 return $ldapUserProvider->loadUserByIdentifier($value)->getEntry();
             } catch (UserNotFoundException $e) {
diff --git a/tools/composer-require-checker.json b/tools/composer-require-checker.json
index 8a6e045..c98b9cd 100644
--- a/tools/composer-require-checker.json
+++ b/tools/composer-require-checker.json
@@ -2,7 +2,6 @@
   "symbol-whitelist": [
     "SimpleSAML\\Module\\ldap\\ConfigHelper",
     "SimpleSAML\\Module\\ldap\\ConnectorFactory",
-    "SimpleSAML\\Module\\ldap\\ConnectorInterface",
-    "Symfony\\Component\\Security\\Core\\Exception\\UserNotFoundException"
+    "SimpleSAML\\Module\\ldap\\ConnectorInterface"
   ]
 }