diff --git a/doc/requirements.txt b/doc/requirements.txt
index 823892f..25808d4 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -11,3 +11,4 @@ python-barcode>=0.11.0,<1
 importlib-metadata
 importlib_resources
 sphinxcontrib.datatemplates
+pycups