diff --git a/android/app/src/main/kotlin/com/vodemn/lightmeter/MainActivity.kt b/android/app/src/main/kotlin/com/vodemn/lightmeter/MainActivity.kt
index a0cbe97..af458c4 100644
--- a/android/app/src/main/kotlin/com/vodemn/lightmeter/MainActivity.kt
+++ b/android/app/src/main/kotlin/com/vodemn/lightmeter/MainActivity.kt
@@ -63,10 +63,10 @@ class MainActivity : FlutterActivity() {
             "com.vodemn.lightmeter/volumeEvents"
         )
         volumeEventChannel.setStreamHandler(object : EventChannel.StreamHandler {
-            override fun onListen(listener: Any, eventSink: EventSink) {
+            override fun onListen(listener: Any?, eventSink: EventSink) {
                 volumeEventsEmitter = eventSink
             }
-            override fun onCancel(listener: Any) {
+            override fun onCancel(listener: Any?) {
                 volumeEventsEmitter = null
             }
         })