diff --git a/doc/conf.py b/doc/conf.py
index 0b6f474ca5c827ec0a193eaeba5eb1e1e6867016..70b4e224eabf6a076c73d7b449d7967cdd4cc169 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -269,4 +269,4 @@ def setup(app):
     # Add `>>>` button to toggle visibility of prompts in code blocks.
     # see https://github.com/readthedocs/sphinx_rtd_theme/issues/167 and
     # https://raw.githubusercontent.com/python/python-docs-theme/master/python_docs_theme/static/copybutton.js
-    app.add_javascript("copybutton.js")
+    app.add_js_file("copybutton.js")