diff --git a/Doc/Makefile b/Doc/Makefile
index 91f937f985831a..a3e099a447ec99 100644
--- a/Doc/Makefile
+++ b/Doc/Makefile
@@ -107,7 +107,7 @@ clean:
 
 venv:
 	$(PYTHON) -m venv venv
-	./venv/bin/python3 -m pip install -U Sphinx
+	./venv/bin/python3 -m pip install -U Sphinx==1.4.9
 
 dist:
 	rm -rf dist