diff --git a/Python/freeze_importlib.py b/Python/freeze_importlib.py
index 9cce0b1..c012722 100644
--- a/Python/freeze_importlib.py
+++ b/Python/freeze_importlib.py
@@ -22,9 +22,9 @@
             line.append('%d,' % c)
         lines.append(''.join(line))
     lines.append('};\n')
-    with open(output_path, 'w') as output_file:
+    with open(output_path, 'w', encoding='utf-8') as output_file:
         output_file.write('\n'.join(lines))
-        output_file.write('\u0000')
+        output_file.write('/* Mercurial binary marker: \x00 */')
 
 
 if __name__ == '__main__':
diff --git a/Python/importlib.h b/Python/importlib.h
index f11dcbb..3a03c46 100644
--- a/Python/importlib.h
+++ b/Python/importlib.h
Binary files differ