diff --git a/src/Symfony/Component/Ldap/Adapter/AbstractQuery.php b/src/Symfony/Component/Ldap/Adapter/AbstractQuery.php
index 4bba5c2ebee40..25a664c24ece3 100644
--- a/src/Symfony/Component/Ldap/Adapter/AbstractQuery.php
+++ b/src/Symfony/Component/Ldap/Adapter/AbstractQuery.php
@@ -32,12 +32,12 @@ public function __construct(ConnectionInterface $connection, string $dn, string
             'maxItems' => 0,
             'sizeLimit' => 0,
             'timeout' => 0,
-            'deref' => static::DEREF_NEVER,
+            'deref' => QueryInterface::DEREF_NEVER,
             'attrsOnly' => 0,
-            'scope' => static::SCOPE_SUB,
+            'scope' => QueryInterface::SCOPE_SUB,
         ));
-        $resolver->setAllowedValues('deref', array(static::DEREF_ALWAYS, static::DEREF_NEVER, static::DEREF_FINDING, static::DEREF_SEARCHING));
-        $resolver->setAllowedValues('scope', array(static::SCOPE_BASE, static::SCOPE_ONE, static::SCOPE_SUB));
+        $resolver->setAllowedValues('deref', array(QueryInterface::DEREF_ALWAYS, QueryInterface::DEREF_NEVER, QueryInterface::DEREF_FINDING, QueryInterface::DEREF_SEARCHING));
+        $resolver->setAllowedValues('scope', array(QueryInterface::SCOPE_BASE, QueryInterface::SCOPE_ONE, QueryInterface::SCOPE_SUB));
 
         $resolver->setNormalizer('filter', function (Options $options, $value) {
             return \is_array($value) ? $value : array($value);
diff --git a/src/Symfony/Component/Ldap/Adapter/ExtLdap/Query.php b/src/Symfony/Component/Ldap/Adapter/ExtLdap/Query.php
index 05e5878bb2a48..ba658663b463e 100644
--- a/src/Symfony/Component/Ldap/Adapter/ExtLdap/Query.php
+++ b/src/Symfony/Component/Ldap/Adapter/ExtLdap/Query.php
@@ -12,6 +12,7 @@
 namespace Symfony\Component\Ldap\Adapter\ExtLdap;
 
 use Symfony\Component\Ldap\Adapter\AbstractQuery;
+use Symfony\Component\Ldap\Adapter\QueryInterface;
 use Symfony\Component\Ldap\Exception\LdapException;
 use Symfony\Component\Ldap\Exception\NotBoundException;
 
@@ -62,20 +63,18 @@ public function execute()
 
             $con = $this->connection->getResource();
 
-            switch ($this->options['scope']) {
-                case static::SCOPE_BASE:
-                    $func = 'ldap_read';
-                    break;
-                case static::SCOPE_ONE:
-                    $func = 'ldap_list';
-                    break;
-                case static::SCOPE_SUB:
-                    $func = 'ldap_search';
-                    break;
-                default:
-                    throw new LdapException(sprintf('Could not search in scope "%s".', $this->options['scope']));
+            $funcMap = array(
+                QueryInterface::SCOPE_BASE => 'ldap_read',
+                QueryInterface::SCOPE_ONE => 'ldap_list',
+                QueryInterface::SCOPE_SUB => 'ldap_search',
+            );
+
+            if (!isset($funcMap[$this->options['scope']])) {
+                throw new LdapException(sprintf('Could not search in scope "%s".', $this->options['scope']));
             }
 
+            $func = $funcMap[$this->options['scope']];
+
             $this->search = @$func(
                 $con,
                 $this->dn,