diff --git a/docs/requirements.txt b/docs/requirements.txt
index 9fb4fbd6..60a6fa15 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,3 +1,3 @@
 partitura
-sphinx>=5
-nbsphinx
+sphinx==6.1.3
+nbsphinx==0.8.12