diff --git a/tox.ini b/tox.ini
index 387ee2183..793a31d98 100644
--- a/tox.ini
+++ b/tox.ini
@@ -38,6 +38,7 @@ deps =
 
 [testenv:docs]
 deps =
+    pygments >= 2.19.1  # Sphinx build fails on 2.19.0 when highlighting ini block
     Sphinx
     readme
     setuptools >= 18.5