diff --git a/src/Symfony/Component/Ldap/Adapter/ExtLdap/Connection.php b/src/Symfony/Component/Ldap/Adapter/ExtLdap/Connection.php
index d2d096c4ba20e..3f757154104c2 100644
--- a/src/Symfony/Component/Ldap/Adapter/ExtLdap/Connection.php
+++ b/src/Symfony/Component/Ldap/Adapter/ExtLdap/Connection.php
@@ -18,6 +18,7 @@
 use Symfony\Component\Ldap\Exception\ConnectionTimeoutException;
 use Symfony\Component\Ldap\Exception\InvalidCredentialsException;
 use Symfony\Component\Ldap\Exception\LdapException;
+use Symfony\Component\Ldap\Exception\NotBoundException;
 use Symfony\Component\OptionsResolver\Options;
 use Symfony\Component\OptionsResolver\OptionsResolver;
 
@@ -116,6 +117,10 @@ public function saslBind(?string $dn = null, #[\SensitiveParameter] ?string $pas
      */
     public function whoami(): string
     {
+        if (!$this->connection) {
+            throw new NotBoundException(\sprintf('Cannot execute "%s()" before calling "%s::saslBind()".', __METHOD__, __CLASS__));
+        }
+
         if (false === $authzId = ldap_exop_whoami($this->connection)) {
             throw new LdapException(ldap_error($this->connection));
         }
diff --git a/src/Symfony/Component/Ldap/Tests/Adapter/ExtLdap/AdapterTest.php b/src/Symfony/Component/Ldap/Tests/Adapter/ExtLdap/AdapterTest.php
index c436c39045c94..5607cdd437603 100644
--- a/src/Symfony/Component/Ldap/Tests/Adapter/ExtLdap/AdapterTest.php
+++ b/src/Symfony/Component/Ldap/Tests/Adapter/ExtLdap/AdapterTest.php
@@ -39,12 +39,39 @@ public function testLdapEscape()
      */
     public function testSaslBind()
     {
+        $h = @ldap_connect(getenv('LDAP_HOST'), getenv('LDAP_PORT'));
+        @ldap_set_option($h, \LDAP_OPT_PROTOCOL_VERSION, 3);
+
+        if (!$h || !@ldap_bind($h)) {
+            $this->markTestSkipped('No server is listening on LDAP_HOST:LDAP_PORT');
+        }
+
+        if (!@ldap_start_tls($h)) {
+            ldap_unbind($h);
+            $this->markTestSkipped('Cannot establish an encrypted connection');
+        }
+
+        ldap_unbind($h);
+
         $ldap = new Adapter($this->getLdapConfig());
 
         $ldap->getConnection()->saslBind('cn=admin,dc=symfony,dc=com', 'symfony');
         $this->assertEquals('cn=admin,dc=symfony,dc=com', $ldap->getConnection()->whoami());
     }
 
+    /**
+     * @group functional
+     */
+    public function testWhoamiWithoutSaslBind()
+    {
+        $ldap = new Adapter($this->getLdapConfig());
+
+        $this->expectException(NotBoundException::class);
+        $this->expectExceptionMessage('Cannot execute "Symfony\Component\Ldap\Adapter\ExtLdap\Connection::whoami()" before calling "Symfony\Component\Ldap\Adapter\ExtLdap\Connection::saslBind()".');
+
+        $ldap->getConnection()->whoami();
+    }
+
     /**
      * @group functional
      */