diff --git a/lmwsip/tests/__init__.py b/lmwsip/tests/__init__.py
index 5222adf..92c0d59 100755
--- a/lmwsip/tests/__init__.py
+++ b/lmwsip/tests/__init__.py
@@ -42,6 +42,10 @@ class lmwsipTest(unittest.TestCase):
         self.login()
         self.assertEqual(type(self.sip.cmd("WN", "DUMMY", "D10", "+00:59", "2020-01-01", "00:00")), str)
 
+    def test_value(self):
+        self.login()
+        self.assertEqual(type(self.sip.value("WN", "DUMMY", "D10")), str)
+
     def test_logout(self):
         self.login()
         self.assertEqual(self.sip.logout(), None)
diff --git a/setup.py b/setup.py
index 8d2d323..b843db4 100644
--- a/setup.py
+++ b/setup.py
@@ -13,6 +13,9 @@ setuptools.setup(
     long_description_content_type="text/markdown",
     url="https://marceln.org/git/Werk/lmwsip",
     packages=setuptools.find_packages(),
+    install_requires=[
+      'python-dateutil',
+    ],
     classifiers=[
         "Programming Language :: Python :: 3",
         "License :: TODO",