diff --git a/tests/unit/test_hash_based_storage.py b/tests/unit/test_hash_based_storage.py
new file mode 100644
index 0000000..4342679
--- /dev/null
+++ b/tests/unit/test_hash_based_storage.py
@@ -0,0 +1,27 @@
+import unittest
+from pyiron_nodes.development import hash_based_storage
+from pyiron_workflow import Workflow
+
+
+@Workflow.wrap.as_function_node("result")
+def add(x, z):
+    return x + z
+
+@Workflow.wrap.as_function_node("result")
+def multiply(z, y):
+    return z * y
+
+
+class TestHashBasedStorage(unittest.TestCase):
+    def test_extract_node_input(self):
+        a = add(1, 2)
+        m = multiply(a, 3)
+        d = hash_based_storage.extract_node_input(m)
+        self.assertTrue("z" in d)
+        self.assertTrue("y" in d)
+        self.assertEqual(d["y"], "3")
+        self.assertTrue(d["z"].startswith("hash"))
+
+
+if __name__ == '__main__':
+    unittest.main()