diff --git a/app/src/main/java/com/tayfuncesur/curvedbottomsheetdemo/WavedActivity.kt b/app/src/main/java/com/tayfuncesur/curvedbottomsheetdemo/WavedActivity.kt
index b845eea..bc73b7e 100644
--- a/app/src/main/java/com/tayfuncesur/curvedbottomsheetdemo/WavedActivity.kt
+++ b/app/src/main/java/com/tayfuncesur/curvedbottomsheetdemo/WavedActivity.kt
@@ -28,6 +28,10 @@ class WavedActivity : AppCompatActivity() {
             view = bottom_sheet,
             type = CurvedBottomSheet.Type.WAVE,
             callback = object : Callback {
+                override fun onStateChanged(p0: View, state: Int) {
+
+                }
+
                 override fun onSlide(p0: View, p1: Float) {
                     contentLayout.alpha = p1
                     dolphinLayout.alpha = 1 - p1
diff --git a/lib/build.gradle b/lib/build.gradle
index b2151c5..bbf58ae 100644
--- a/lib/build.gradle
+++ b/lib/build.gradle
@@ -9,8 +9,8 @@ android {
     defaultConfig {
         minSdkVersion 16
         targetSdkVersion 28
-        versionCode 4
-        versionName "1.1"
+        versionCode 5
+        versionName "1.2"
     }
 }
 
diff --git a/lib/src/main/java/com/tayfuncesur/curvedbottomsheet/Callback.kt b/lib/src/main/java/com/tayfuncesur/curvedbottomsheet/Callback.kt
index e36d852..a05e1c4 100644
--- a/lib/src/main/java/com/tayfuncesur/curvedbottomsheet/Callback.kt
+++ b/lib/src/main/java/com/tayfuncesur/curvedbottomsheet/Callback.kt
@@ -4,4 +4,5 @@ import android.view.View
 
 interface Callback {
     fun onSlide(p0: View, p1: Float)
+    fun onStateChanged(p0: View, state: Int)
 }
\ No newline at end of file
diff --git a/lib/src/main/java/com/tayfuncesur/curvedbottomsheet/CurvedBottomSheet.kt b/lib/src/main/java/com/tayfuncesur/curvedbottomsheet/CurvedBottomSheet.kt
index c7094c6..9f78f65 100644
--- a/lib/src/main/java/com/tayfuncesur/curvedbottomsheet/CurvedBottomSheet.kt
+++ b/lib/src/main/java/com/tayfuncesur/curvedbottomsheet/CurvedBottomSheet.kt
@@ -46,14 +46,14 @@ class CurvedBottomSheet(
                 }
 
                 override fun onStateChanged(p0: View, p1: Int) {
-
+                    callback?.onStateChanged(p0, p1)
                 }
             })
         } else {
             topSheetBehavior = TopSheetBehavior.from(view)
             topSheetBehavior.setTopSheetCallback(object : TopSheetBehavior.TopSheetCallback() {
                 override fun onStateChanged(bottomSheet: View, newState: Int) {
-
+                    callback?.onStateChanged(bottomSheet, newState)
                 }
 
                 override fun onSlide(bottomSheet: View, slideOffset: Float, isOpening: Boolean?) {