diff --git a/AUTHORS.md b/AUTHORS.md
index 4fb77ffb..a0860229 100644
--- a/AUTHORS.md
+++ b/AUTHORS.md
@@ -85,6 +85,7 @@ date of first contribution):
   * [Luke McKechnie](https://github.com/galamdring)
   * [Peter Backx](https://github.com/pbackx)
   * [Josh Major](https://github.com/astateofblank)
+  * ["alex-gh"](https://github.com/alex-gh)
 
 OctoPrint started off as a fork of [Cura](https://github.com/daid/Cura) by
 [Daid Braam](https://github.com/daid). Parts of its communication layer and
diff --git a/src/octoprint/util/comm.py b/src/octoprint/util/comm.py
index 394f9cc9..44a6605a 100644
--- a/src/octoprint/util/comm.py
+++ b/src/octoprint/util/comm.py
@@ -2472,8 +2472,8 @@ class MachineCom(object):
 	def _do_send_with_checksum(self, command, linenumber):
 		command_to_send = "N" + str(linenumber) + " " + command
 		checksum = 0
-		for c in command_to_send:
-			checksum ^= ord(c)
+		for c in bytearray(command_to_send):
+			checksum ^= c
 		command_to_send = command_to_send + "*" + str(checksum)
 		self._do_send_without_checksum(command_to_send)