diff --git a/setup.cfg b/setup.cfg
index c13da1a..7621294 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -43,6 +43,7 @@ install_requires =
     openpyxl>=3.1.2,<4.0
     xlrd>=2.0.1,<3.0
     beangulp @ git+https://github.com/beancount/beangulp.git@master
+    python-dateutil>=2.9.0
 
 
 [options.packages.find]