diff --git a/docs/requirements.txt b/docs/requirements.txt
index b75b037..4b88d38 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -9,4 +9,5 @@ sphinx-autoapi
 sphinx-copybutton
 sphinx-book-theme
 astroquery
-astropy
\ No newline at end of file
+astropy
+matplotlib
\ No newline at end of file