diff --git a/src/Client.php b/src/Client.php
index 5c27fb1..cdf0557 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -211,8 +211,8 @@ public function setProtocol(RdapProtocolInterface $protocol): void
     {
         foreach (self::PROTOCOLS as $protocolVersion => $obj) {
             if (is_a($protocol, $obj)) {
-                $this->protocols[$protocolVersion] = $obj;
-                break;
+                $this->protocols[$protocolVersion] = $protocol;
+                return;
             }
         }
         throw new InvalidServiceDefinitionException(