diff --git a/tools/gencert/cbytes.py b/tools/gencert/cbytes.py
index 9c1f507..4520634 100644
--- a/tools/gencert/cbytes.py
+++ b/tools/gencert/cbytes.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+# -*- coding: utf-8 -*-
 #
 # Copyright (C) 2018 SoloKeys, Inc. <https://solokeys.com/>
 #
diff --git a/tools/gencert/dump_pem.py b/tools/gencert/dump_pem.py
index ec78ca6..c313f19 100644
--- a/tools/gencert/dump_pem.py
+++ b/tools/gencert/dump_pem.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+# -*- coding: utf-8 -*-
 #
 # Copyright (C) 2018 SoloKeys, Inc. <https://solokeys.com/>
 #
diff --git a/tools/gencert/print_x_y.py b/tools/gencert/print_x_y.py
index b527264..5083c49 100644
--- a/tools/gencert/print_x_y.py
+++ b/tools/gencert/print_x_y.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
 #
 # Copyright (C) 2018 SoloKeys, Inc. <https://solokeys.com/>
 #