diff --git a/src/watchdog/watchmedo.py b/src/watchdog/watchmedo.py
index bef953c2..304b6fe6 100755
--- a/src/watchdog/watchmedo.py
+++ b/src/watchdog/watchmedo.py
@@ -376,7 +376,7 @@ def tricks_generate_yaml(args):
     else:
         if not os.path.exists(args.append_to_file):
             content = header + content
-        with open(args.append_to_file, "ab") as output:
+        with open(args.append_to_file, "a", encoding="utf-8") as output:
             output.write(content)