diff --git a/build.py b/build.py
index ef1a4d9..d441fba 100755
--- a/build.py
+++ b/build.py
@@ -21,13 +21,14 @@ def main():
     web = os.path.join(out, 'web')
     if os.path.exists(web):
         shutil.rmtree(web)
+    os.makedirs(web)
     gen = os.path.join(web, time_id)
     css = os.path.join(gen, style)
     js = os.path.join(gen, script)
     #
     run('rsync', '--archive', f'{input_directory}/', f'{web}/')
     for directory in [css, js]:
-        os.makedirs(directory, exist_ok=True)
+        os.makedirs(directory)
     #
     link_gv = os.path.join(root, 'link.gv')
     link_svg = os.path.join(gen, 'link.svg')