diff --git a/app/src/main/java/eu/wa5p/lightmeter/MainActivity.kt b/app/src/main/java/eu/wa5p/lightmeter/MainActivity.kt
index 5cc4e17..85815b8 100644
--- a/app/src/main/java/eu/wa5p/lightmeter/MainActivity.kt
+++ b/app/src/main/java/eu/wa5p/lightmeter/MainActivity.kt
@@ -55,7 +55,7 @@ class MainActivity : ComponentActivity(), SensorEventListener {
         illuminanceSensor = sensorManager.getDefaultSensor(Sensor.TYPE_LIGHT)
     }
 
-    fun updateLightmeterState(illuminance: Double) {
+    private fun updateLightmeterState(illuminance: Double) {
         val iso = lightmeterState.value.iso
         val aperture = lightmeterState.value.aperture
         val shutterSpeed = (aperture * aperture) / (illuminance * (iso / 100))