diff --git a/setup.cfg b/setup.cfg
index ae8085e..4101734 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -33,7 +33,6 @@ packages = find:
 python_requires = >=3.8
 install_requires =
     typing-extensions ~= 4.3
-    python-dateutil
 
 [options.packages.find]
 where = src
@@ -46,4 +45,5 @@ testing =
     coverage-conditional-plugin ~= 0.5
     flake8 ~= 7.0
     mypy ~= 1.9
+    python-dateutil
     types-python-dateutil