diff --git a/doc_requirements.txt b/doc_requirements.txt
index 8e00ab2..632a1c9 100644
--- a/doc_requirements.txt
+++ b/doc_requirements.txt
@@ -2,6 +2,6 @@ sphinxcontrib-napoleon
 sphinxcontrib-programoutput
 sphinxcontrib-inlinesyntaxhighlight
 numpy
-marshmallow==3.0.0rc6
+marshmallow==3.26.2
 pytest
 rstcheck