diff --git a/.gitignore b/.gitignore
index 18f4997..e3b96dd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,6 +15,8 @@ coverage.xml
 
 # Sphinx documentation
 docs/_build
+# nbextensions installed as part of sphinx-build
+docs/source/nbextensions
 # auto-generated Sphinx files
 docs/source/nbextensions.rst