diff --git a/arpes/utilities/dict.py b/arpes/utilities/dict.py
index 340f980b..729b160b 100644
--- a/arpes/utilities/dict.py
+++ b/arpes/utilities/dict.py
@@ -1,8 +1,9 @@
 """Utilities for modifying, iterating over, and transforming dictionaries."""
+
 from __future__ import annotations
 
 import re
-from typing import Any
+from typing import Any, TypeVar
 
 from .xarray import lift_dataarray_attrs, lift_datavar_attrs
 
@@ -45,14 +46,24 @@ def rename_keys(
     return d
 
 
-def clean_keys(d: dict[str, Any]) -> dict[str, Any]:
-    """Renames dictionary keys so that they are more Pythonic."""
+T = TypeVar("T")
+
+
+def clean_keys(d: dict[str, T]) -> dict[str, T]:
+    """Renames dict key to fit Pythonic more.
+
+    Args:
+        d (dict): dictionary to be cleaned.
+
+    Returns:
+        dict object whose key is cleaned.
+    """
 
     def clean_single_key(k: str) -> str:
         k = k.replace(" ", "_")
         k = k.replace(".", "_")
         k = k.lower()
-        k = re.sub(r"[()/?]", "", k)
+        k = re.sub(r"[()/?]", "_", k)
         return k.replace("__", "_")
 
     return dict(zip([clean_single_key(k) for k in d], d.values(), strict=True))
diff --git a/tests/test_generic_utilities.py b/tests/test_generic_utilities.py
index 505592b8..671d4413 100644
--- a/tests/test_generic_utilities.py
+++ b/tests/test_generic_utilities.py
@@ -1,7 +1,15 @@
 """Test for generic utility."""
+
 import pytest
 
-from arpes.utilities import deep_equals, deep_update
+from arpes.utilities import clean_keys, deep_equals, deep_update
+
+
+def test_cldean_keys() -> None:
+    """Test for clean_keys."""
+    test_dict = {"Excitation Energy": 4.03, "Count/Cycle": 100}
+    cleaned_dict = clean_keys(test_dict)
+    assert cleaned_dict == {"excitation_energy": 4.03, "count_cycle": 100}
 
 
 @pytest.mark.parametrize(
@@ -19,7 +27,7 @@ def test_deep_equals(
     *,
     expected_equal: bool,
 ) -> None:
-    """[TODO:summary].
+    """Test for deep_equals.
 
     [TODO:description]