diff --git a/src/Factory.php b/src/Factory.php
index 17dce82..58bbcd7 100644
--- a/src/Factory.php
+++ b/src/Factory.php
@@ -111,6 +111,12 @@ public function awaitLogin(Client $client, $user, $pass)
                     return;
                 }
 
+                // reject if core rejects initialization
+                if ($type === 'ClientInitReject') {
+                    $reject(new \RuntimeException('Connection rejected by Quassel core: ' . $data['Error']));
+                    return $client->close();
+                }
+
                 // reject promise if login is rejected
                 if ($type === 'ClientLoginReject') {
                     $reject(new \RuntimeException('Unable to log in: ' . $data['Error']));
@@ -125,6 +131,10 @@ public function awaitLogin(Client $client, $user, $pass)
 
                     return;
                 }
+
+                // otherwise reject if we receive an unexpected message
+                $reject(new \RuntimeException('Received unexpected "' . $type . '" message during login'));
+                $client->close();
             });
 
             // reject promise if client emits error
diff --git a/tests/FactoryIntegrationTest.php b/tests/FactoryIntegrationTest.php
index d27ebb4..7ad4bc2 100644
--- a/tests/FactoryIntegrationTest.php
+++ b/tests/FactoryIntegrationTest.php
@@ -154,6 +154,64 @@ public function testCreateClientWithAuthRejectsIfServerClosesAfterClientInit()
         Block\await($promise, $loop, 10.0);
     }
 
+    /**
+     * @expectedException RuntimeException
+     */
+    public function testCreateClientWithAuthRejectsIfServerSendsClientInitRejectAfterClientInit()
+    {
+        $loop = LoopFactory::create();
+        $server = new Server(0, $loop);
+
+        $server->on('connection', function (ConnectionInterface $conn) {
+            $conn->once('data', function () use ($conn) {
+                $conn->write("\x00\x00\x00\x02");
+
+                $conn->on('data', function () use ($conn) {
+                    // respond with rejection
+                    $conn->write(FactoryIntegrationTest::encode(array(
+                        'MsgType' => 'ClientInitReject',
+                        'Error' => 'Too old'
+                    )));
+                });
+            });
+        });
+
+        $uri = str_replace('tcp://', '', $server->getAddress());
+        $factory = new Factory($loop);
+        $promise = $factory->createClient('user:pass@' . $uri);
+
+        Block\await($promise, $loop, 10.0);
+    }
+
+    /**
+     * @expectedException RuntimeException
+     */
+    public function testCreateClientWithAuthRejectsIfServerSendsUnknownMessageAfterClientInit()
+    {
+        $loop = LoopFactory::create();
+        $server = new Server(0, $loop);
+
+        $server->on('connection', function (ConnectionInterface $conn) {
+            $conn->once('data', function () use ($conn) {
+                $conn->write("\x00\x00\x00\x02");
+
+                $conn->on('data', function () use ($conn) {
+                    // respond with unknown message
+                    $conn->write(FactoryIntegrationTest::encode(array(
+                        'MsgType' => 'Unknown',
+                        'Error' => 'Ignored'
+                    )));
+                });
+            });
+        });
+
+        $uri = str_replace('tcp://', '', $server->getAddress());
+        $factory = new Factory($loop);
+        $promise = $factory->createClient('user:pass@' . $uri);
+
+        Block\await($promise, $loop, 10.0);
+    }
+
     /**
      * @expectedException RuntimeException
      */