diff --git a/lib/net/ldap/connection.rb b/lib/net/ldap/connection.rb
index 61aacb53..9cae456a 100644
--- a/lib/net/ldap/connection.rb
+++ b/lib/net/ldap/connection.rb
@@ -606,7 +606,7 @@ def password_modify(args)
     pdu = queued_read(message_id)
 
     if !pdu || pdu.app_tag != Net::LDAP::PDU::ExtendedResponse
-      raise Net::LDAP::ResponseMissingError, "response missing or invalid"
+      raise Net::LDAP::ResponseMissingOrInvalidError, "response missing or invalid"
     end
 
     pdu