diff --git a/doc/manual/requirements.txt b/doc/manual/requirements.txt
index 6fec401..101045d 100644
--- a/doc/manual/requirements.txt
+++ b/doc/manual/requirements.txt
@@ -1,7 +1,7 @@
 # Extra packages required for building documentation on ReadTheDocs
 
 Sphinx==2.1.2
-Pygments==2.15.0
+Pygments==2.20.0
 sphinx-rtd-theme
 readthedocs-sphinx-ext
 breathe==4.13.1