diff --git a/tests/types/test_type_helpers.py b/tests/types/test_type_helpers.py
index f7cefd0..3ab5953 100644
--- a/tests/types/test_type_helpers.py
+++ b/tests/types/test_type_helpers.py
@@ -101,5 +101,60 @@ def test_is_list_of():
     assert is_list_of(["x", 2], (str, int)) is True
 
 
+def test_is_dict_of_edge_cases():
+    # Test empty dictionary
+    assert is_dict_of({}, key_allowed_types=str) is True, (
+        "Empty dictionary should return True"
+    )
+    # Test None as input
+    assert is_dict_of(None, key_allowed_types=str) is False, (
+        "None input should return False"
+    )
+    # Test dictionary with a None value
+    assert (
+        is_dict_of(
+            {"key": None},
+            key_allowed_types=str,
+            value_allowed_types=(str, type(None)),
+        )
+        is True
+    ), "Dictionary with None value should pass if None is an allowed type"
+    # Test nested dictionary by specifying allowed value types that do not include dict
+    assert (
+        is_dict_of(
+            {"key": {"nested_key": "value"}},
+            key_allowed_types=str,
+            value_allowed_types=(str, int),
+        )
+        is False
+    ), (
+        "Nested dictionaries should return False if dict is not an allowed value type"
+    )
+    # Test nested dictionary when no value types are specified (documents current behavior)
+    assert (
+        is_dict_of({"key": {"nested_key": "value"}}, key_allowed_types=str)
+        is True
+    ), "Nested dictionaries are allowed when value types are not specified"
+
+
+def test_is_list_of_edge_cases():
+    # Test empty list
+    assert is_list_of([], str) is True, "Empty list should return True"
+    # Test None as input
+    assert is_list_of(None, str) is False, "None input should return False"
+    # Test list with a None value
+    assert is_list_of([None], str) is False, (
+        "List with None value should return False if None is not an allowed type"
+    )
+    # Test list with a None value where None is an allowed type
+    assert is_list_of([None], (str, type(None))) is True, (
+        "List with None value should pass if None is an allowed type"
+    )
+    # Test nested list
+    assert is_list_of([["a", "b"]], str) is False, (
+        "Nested lists should return False"
+    )
+
+
 if __name__ == "__main__":
     raise SystemExit(pytest.main([__file__]))