diff --git a/homeassistant/components/zha/sensor.py b/homeassistant/components/zha/sensor.py
index 9fd8892b977..e81d3a9655f 100644
--- a/homeassistant/components/zha/sensor.py
+++ b/homeassistant/components/zha/sensor.py
@@ -403,9 +403,9 @@ class Illuminance(Sensor):
     _attr_name: str = "Illuminance"
     _attr_native_unit_of_measurement = LIGHT_LUX
 
-    def formatter(self, value: int) -> float:
+    def formatter(self, value: int) -> int:
         """Convert illumination data."""
-        return round(pow(10, ((value - 1) / 10000)), 1)
+        return round(pow(10, ((value - 1) / 10000)))
 
 
 @MULTI_MATCH(
diff --git a/tests/components/zha/test_sensor.py b/tests/components/zha/test_sensor.py
index 55ea9833caa..dec065936a1 100644
--- a/tests/components/zha/test_sensor.py
+++ b/tests/components/zha/test_sensor.py
@@ -129,7 +129,7 @@ async def async_test_pressure(hass, cluster, entity_id):
 async def async_test_illuminance(hass, cluster, entity_id):
     """Test illuminance sensor."""
     await send_attributes_report(hass, cluster, {1: 1, 0: 10, 2: 20})
-    assert_state(hass, entity_id, "1.0", LIGHT_LUX)
+    assert_state(hass, entity_id, "1", LIGHT_LUX)
 
 
 async def async_test_metering(hass, cluster, entity_id):