diff --git a/phpseclib/Net/SSH2.php b/phpseclib/Net/SSH2.php
index 5bdb9cef..a1cfd3f3 100644
--- a/phpseclib/Net/SSH2.php
+++ b/phpseclib/Net/SSH2.php
@@ -1523,7 +1523,7 @@ class SSH2
                 $this->updateLogHistory('UNKNOWN (32)', 'SSH_MSG_KEXDH_GEX_INIT');
         }
 
-        $response = $this->get_binary_packet_or_close(constant($serverKexReplyMessage));
+        $response = $this->get_binary_packet_or_close($serverKexReplyMessage);
 
         [
             $type,
@@ -2394,7 +2394,7 @@ class SSH2
         $response = $this->get_binary_packet_or_close(
             MessageType::USERAUTH_SUCCESS,
             MessageType::USERAUTH_FAILURE,
-            MessageType::USERAUTH_PK_OK
+            MessageTypeExtra::USERAUTH_PK_OK
         );
 
         [$type] = Strings::unpackSSH2('C', $response);
diff --git a/tests/Unit/Net/SSH2UnitTest.php b/tests/Unit/Net/SSH2UnitTest.php
index d66607d7..3489c48a 100644
--- a/tests/Unit/Net/SSH2UnitTest.php
+++ b/tests/Unit/Net/SSH2UnitTest.php
@@ -287,7 +287,7 @@ class SSH2UnitTest extends PhpseclibTestCase
             });
         $ssh->expects($this->once())
             ->method('send_binary_packet')
-            ->with(Strings::packSSH2('CNs', NET_SSH2_MSG_CHANNEL_DATA, 1, 'hello world'));
+            ->with(Strings::packSSH2('CNs', SSH2\MessageType::CHANNEL_DATA, 1, 'hello world'));
         self::setVar($ssh, 'server_channels', [1 => 1]);
         self::setVar($ssh, 'packet_size_client_to_server', [1 => 0x7FFFFFFF]);
         self::setVar($ssh, 'window_size_client_to_server', [1 => 0]);
@@ -314,7 +314,7 @@ class SSH2UnitTest extends PhpseclibTestCase
             });
         $ssh->expects($this->once())
             ->method('send_binary_packet')
-            ->with(Strings::packSSH2('CNs', NET_SSH2_MSG_CHANNEL_DATA, 1, ' world'));
+            ->with(Strings::packSSH2('CNs', SSH2\MessageType::CHANNEL_DATA, 1, ' world'));
         self::setVar($ssh, 'channel_buffers_write', [1 => 'hello']);
         self::setVar($ssh, 'server_channels', [1 => 1]);
         self::setVar($ssh, 'packet_size_client_to_server', [1 => 0x7FFFFFFF]);
@@ -345,7 +345,7 @@ class SSH2UnitTest extends PhpseclibTestCase
             });
         $ssh->expects($this->once())
             ->method('send_binary_packet')
-            ->with(Strings::packSSH2('CNs', NET_SSH2_MSG_CHANNEL_DATA, 1, 'hello'));
+            ->with(Strings::packSSH2('CNs', SSH2\MessageType::CHANNEL_DATA, 1, 'hello'));
         self::setVar($ssh, 'server_channels', [1 => 1]);
         self::setVar($ssh, 'packet_size_client_to_server', [1 => 0x7FFFFFFF]);
         self::setVar($ssh, 'window_size_client_to_server', [1 => 5]);