diff --git a/microcosm/loaders.py b/microcosm/loaders.py
index <HASH>..<HASH> 100644
--- a/microcosm/loaders.py
+++ b/microcosm/loaders.py
@@ -22,7 +22,7 @@ def expand_config(dct,
                   skip_to=0,
                   key_func=lambda key: key.lower(),
                   key_parts_filter=lambda key_parts: True,
-                  value_func=lambda value: value() if callable(value) else value):
+                  value_func=lambda value: value):
     """
     Expand a dictionary recursively by splitting keys along the separator.
 
diff --git a/microcosm/tests/test_loaders.py b/microcosm/tests/test_loaders.py
index <HASH>..<HASH> 100644
--- a/microcosm/tests/test_loaders.py
+++ b/microcosm/tests/test_loaders.py
@@ -65,6 +65,7 @@ def test_expand_config():
             },
             key_parts_filter=lambda key_parts: key_parts[0] == "prefix",
             skip_to=1,
+            value_func=lambda value: value() if callable(value) else value,
         ),
         is_(equal_to(
             {
Don't evaluate values as callable by default