diff --git a/src/octoprint/plugins/softwareupdate/scripts/update-octoprint.py b/src/octoprint/plugins/softwareupdate/scripts/update-octoprint.py
index fdb065e6..9c6a600f 100644
--- a/src/octoprint/plugins/softwareupdate/scripts/update-octoprint.py
+++ b/src/octoprint/plugins/softwareupdate/scripts/update-octoprint.py
@@ -27,7 +27,9 @@ def _log(lines, prefix=None, stream=None):
 		output_stream = sys.stderr
 
 	for line in lines:
-		print(u"{} {}".format(prefix, _to_unicode(line.rstrip(), errors="replace")), file=output_stream)
+		to_print = _to_str(u"{} {}".format(prefix, _to_unicode(line.rstrip(), errors="replace")),
+		                   errors="replace")
+		print(to_print, file=output_stream)
 
 
 def _to_unicode(s_or_u, encoding="utf-8", errors="strict"):
@@ -38,6 +40,14 @@ def _to_unicode(s_or_u, encoding="utf-8", errors="strict"):
 		return s_or_u
 
 
+def _to_str(s_or_u, encoding="utf-8", errors="strict"):
+	"""Make sure ``s_or_u`` is a str."""
+	if isinstance(s_or_u, unicode):
+		return s_or_u.encode(encoding, errors=errors)
+	else:
+		return s_or_u
+
+
 def _execute(command, **kwargs):
 	import sarge