diff --git a/src/ifctester/pyproject.toml b/src/ifctester/pyproject.toml
index d5adce1193..a4644df54c 100644
--- a/src/ifctester/pyproject.toml
+++ b/src/ifctester/pyproject.toml
@@ -15,7 +15,7 @@ classifiers = [
     "Programming Language :: Python :: 3",
     "License :: OSI Approved :: GNU Lesser General Public License v3 or later (LGPLv3+)",
 ]
-dependencies = ["ifcopenshell", "dateutil", "xmlschema", "numpy"]
+dependencies = ["ifcopenshell", "python-dateutil", "xmlschema", "numpy"]
 
 [project.urls]
 Homepage = "http://ifcopenshell.org"