diff --git a/doc/requirements-doc.txt b/doc/requirements-doc.txt
index c4d92868e..4e89c01b7 100644
--- a/doc/requirements-doc.txt
+++ b/doc/requirements-doc.txt
@@ -1,5 +1,6 @@
 click
 colorama
+colorful
 filelock
 flask
 flatbuffers