diff --git a/docs/requirements.txt b/docs/requirements.txt
index beca841a..0ad0adbb 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,4 +1,4 @@
 alabaster==0.7.12
 Sphinx==4.0.2
 sphinx-rtd-theme==0.5.2
-sphinx-copybutton==0.3.3
+sphinx-copybutton==0.4.0