diff --git a/tests/unit/test_add_dtypes_mapper_types.py b/tests/unit/test_add_dtypes_mapper_types.py
index 7bbf26c..8d7352d 100644
--- a/tests/unit/test_add_dtypes_mapper_types.py
+++ b/tests/unit/test_add_dtypes_mapper_types.py
@@ -23,6 +23,14 @@
     expected_dtype="timestamp[ms,UTC][pyarrow]",
     additional_mapper_dicts={"datetime64[ms]": "timestamp[ms,UTC][pyarrow]"},
 )
+@Parametrization.case(
+    name="test simple type mapping override with additional_mapper_dicts ms",
+    df_data=pd.DataFrame(
+        {"test_column": [0.0000000001, 2.0, 3.0, None]}, dtype="float64"
+    ),
+    expected_dtype="float32[pyarrow]",
+    additional_mapper_dicts={"float64": "float32[pyarrow]"},
+)
 def test_add_dtypes_types(df_data, expected_dtype, additional_mapper_dicts):
     sa = SchemArrow(custom_mapper=additional_mapper_dicts)
     adf = sa(df_data)