diff --git a/src/PAMI/Client/Impl/ClientImpl.php b/src/PAMI/Client/Impl/ClientImpl.php
index 204d528c8..8a66fbf4e 100644
--- a/src/PAMI/Client/Impl/ClientImpl.php
+++ b/src/PAMI/Client/Impl/ClientImpl.php
@@ -328,7 +328,7 @@ public function process()
             } elseif ($evePos !== false) {
                 $event = $this->messageToEvent($aMsg);
                 $response = $this->findResponse($event);
-                if ($response === false || $response->isComplete()) {
+                if (!($response instanceof ResponseMessage) || $response->isComplete()) {
                     $this->dispatch($event);
                 } else {
                     $response->addEvent($event);
@@ -340,7 +340,9 @@ public function process()
                 $bMsg .= 'ActionId: ' . $this->lastActionId . "\r\n" . $aMsg;
                 $event = $this->messageToEvent($bMsg);
                 $response = $this->findResponse($event);
-                $response->addEvent($event);
+                if ($response instanceof ResponseMessage) {
+                    $response->addEvent($event);
+                }
             }
             $this->logger->debug('----------------');
         }