diff --git a/doc/requirements.txt b/doc/requirements.txt
index 09e59da..b5f0851 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -8,3 +8,4 @@ setuptools-scm
 docutils>=0.12
 sphinxcontrib-spelling>=7.2.0
 python-barcode>=0.11.0,<1
+importlib-metadata