diff --git a/src/Auth/Source/LdapMulti.php b/src/Auth/Source/LdapMulti.php
index 864469eb5..a4f2472dc 100644
--- a/src/Auth/Source/LdapMulti.php
+++ b/src/Auth/Source/LdapMulti.php
@@ -119,7 +119,7 @@ protected function login(string $username, #[\SensitiveParameter]string $passwor
 
         $authsource = $this->mapping[$organization]['authsource'];
 
-        if (array_key_exists($organization, $this->ldapOrgs)) {
+        if (!array_key_exists($organization, $this->ldapOrgs)) {
             // The organization is unknown to us.
             throw new Error\Error('WRONGUSERPASS');
         }