diff --git a/requirements/doc.txt b/requirements/doc.txt
index 64f4d287..643fc9a9 100644
--- a/requirements/doc.txt
+++ b/requirements/doc.txt
@@ -1,4 +1,4 @@
-numpy
-matplotlib
+numpy>=1.21
+matplotlib>=3.5
 pydata-sphinx-theme>=0.11
-sphinx
+sphinx>=5.2