diff --git a/tests/util/test_unit_system.py b/tests/util/test_unit_system.py
index fc8da540d3db0f..2331ff084121e3 100644
--- a/tests/util/test_unit_system.py
+++ b/tests/util/test_unit_system.py
@@ -389,76 +389,58 @@ def test_get_unit_system_invalid(key: str) -> None:
 
 
 @pytest.mark.parametrize(
-    "unit_system, device_class, original_unit, state_unit",
+    "device_class, original_unit, state_unit",
     (
-        (METRIC_SYSTEM, SensorDeviceClass.DISTANCE, LENGTH_FEET, LENGTH_METERS),
-        (METRIC_SYSTEM, SensorDeviceClass.DISTANCE, LENGTH_INCHES, LENGTH_MILLIMETERS),
-        (METRIC_SYSTEM, SensorDeviceClass.DISTANCE, LENGTH_MILES, LENGTH_KILOMETERS),
-        (METRIC_SYSTEM, SensorDeviceClass.DISTANCE, LENGTH_YARD, LENGTH_METERS),
-        (METRIC_SYSTEM, SensorDeviceClass.DISTANCE, LENGTH_KILOMETERS, None),
-        (METRIC_SYSTEM, SensorDeviceClass.DISTANCE, "very_long", None),
+        # Test distance conversion
+        (SensorDeviceClass.DISTANCE, LENGTH_FEET, LENGTH_METERS),
+        (SensorDeviceClass.DISTANCE, LENGTH_INCHES, LENGTH_MILLIMETERS),
+        (SensorDeviceClass.DISTANCE, LENGTH_MILES, LENGTH_KILOMETERS),
+        (SensorDeviceClass.DISTANCE, LENGTH_YARD, LENGTH_METERS),
+        (SensorDeviceClass.DISTANCE, LENGTH_KILOMETERS, None),
+        (SensorDeviceClass.DISTANCE, "very_long", None),
         # Test speed conversion
-        (
-            METRIC_SYSTEM,
-            SensorDeviceClass.SPEED,
-            SPEED_FEET_PER_SECOND,
-            SPEED_KILOMETERS_PER_HOUR,
-        ),
-        (
-            METRIC_SYSTEM,
-            SensorDeviceClass.SPEED,
-            SPEED_MILES_PER_HOUR,
-            SPEED_KILOMETERS_PER_HOUR,
-        ),
-        (METRIC_SYSTEM, SensorDeviceClass.SPEED, SPEED_KILOMETERS_PER_HOUR, None),
-        (METRIC_SYSTEM, SensorDeviceClass.SPEED, SPEED_KNOTS, None),
-        (METRIC_SYSTEM, SensorDeviceClass.SPEED, SPEED_METERS_PER_SECOND, None),
-        (METRIC_SYSTEM, SensorDeviceClass.SPEED, "very_fast", None),
-        (
-            US_CUSTOMARY_SYSTEM,
-            SensorDeviceClass.DISTANCE,
-            LENGTH_CENTIMETERS,
-            LENGTH_INCHES,
-        ),
-        (
-            US_CUSTOMARY_SYSTEM,
-            SensorDeviceClass.DISTANCE,
-            LENGTH_KILOMETERS,
-            LENGTH_MILES,
-        ),
-        (US_CUSTOMARY_SYSTEM, SensorDeviceClass.DISTANCE, LENGTH_METERS, LENGTH_FEET),
-        (
-            US_CUSTOMARY_SYSTEM,
-            SensorDeviceClass.DISTANCE,
-            LENGTH_MILLIMETERS,
-            LENGTH_INCHES,
-        ),
-        (US_CUSTOMARY_SYSTEM, SensorDeviceClass.DISTANCE, LENGTH_MILES, None),
-        (US_CUSTOMARY_SYSTEM, SensorDeviceClass.DISTANCE, "very_long", None),
+        (SensorDeviceClass.SPEED, SPEED_FEET_PER_SECOND, SPEED_KILOMETERS_PER_HOUR),
+        (SensorDeviceClass.SPEED, SPEED_MILES_PER_HOUR, SPEED_KILOMETERS_PER_HOUR),
+        (SensorDeviceClass.SPEED, SPEED_KILOMETERS_PER_HOUR, None),
+        (SensorDeviceClass.SPEED, SPEED_KNOTS, None),
+        (SensorDeviceClass.SPEED, SPEED_METERS_PER_SECOND, None),
+        (SensorDeviceClass.SPEED, "very_fast", None),
+    ),
+)
+def test_get_metric_converted_unit_(
+    device_class: SensorDeviceClass,
+    original_unit: str,
+    state_unit: str | None,
+) -> None:
+    """Test unit conversion rules."""
+    unit_system = METRIC_SYSTEM
+    assert unit_system.get_converted_unit(device_class, original_unit) == state_unit
+
+
+@pytest.mark.parametrize(
+    "device_class, original_unit, state_unit",
+    (
+        # Test distance conversion
+        (SensorDeviceClass.DISTANCE, LENGTH_CENTIMETERS, LENGTH_INCHES),
+        (SensorDeviceClass.DISTANCE, LENGTH_KILOMETERS, LENGTH_MILES),
+        (SensorDeviceClass.DISTANCE, LENGTH_METERS, LENGTH_FEET),
+        (SensorDeviceClass.DISTANCE, LENGTH_MILLIMETERS, LENGTH_INCHES),
+        (SensorDeviceClass.DISTANCE, LENGTH_MILES, None),
+        (SensorDeviceClass.DISTANCE, "very_long", None),
         # Test speed conversion
-        (
-            US_CUSTOMARY_SYSTEM,
-            SensorDeviceClass.SPEED,
-            SPEED_METERS_PER_SECOND,
-            SPEED_MILES_PER_HOUR,
-        ),
-        (
-            US_CUSTOMARY_SYSTEM,
-            SensorDeviceClass.SPEED,
-            SPEED_KILOMETERS_PER_HOUR,
-            SPEED_MILES_PER_HOUR,
-        ),
-        (US_CUSTOMARY_SYSTEM, SensorDeviceClass.SPEED, SPEED_FEET_PER_SECOND, None),
-        (US_CUSTOMARY_SYSTEM, SensorDeviceClass.SPEED, SPEED_KNOTS, None),
-        (US_CUSTOMARY_SYSTEM, SensorDeviceClass.SPEED, SPEED_MILES_PER_HOUR, None),
-        (US_CUSTOMARY_SYSTEM, SensorDeviceClass.SPEED, "very_fast", None),
+        (SensorDeviceClass.SPEED, SPEED_METERS_PER_SECOND, SPEED_MILES_PER_HOUR),
+        (SensorDeviceClass.SPEED, SPEED_KILOMETERS_PER_HOUR, SPEED_MILES_PER_HOUR),
+        (SensorDeviceClass.SPEED, SPEED_FEET_PER_SECOND, None),
+        (SensorDeviceClass.SPEED, SPEED_KNOTS, None),
+        (SensorDeviceClass.SPEED, SPEED_MILES_PER_HOUR, None),
+        (SensorDeviceClass.SPEED, "very_fast", None),
     ),
 )
-def test_get_converted_unit(
-    unit_system: UnitSystem,
+def test_get_us_converted_unit(
     device_class: SensorDeviceClass,
     original_unit: str,
     state_unit: str | None,
 ) -> None:
     """Test unit conversion rules."""
+    unit_system = US_CUSTOMARY_SYSTEM
     assert unit_system.get_converted_unit(device_class, original_unit) == state_unit