diff --git a/app/build.gradle b/app/build.gradle
index 97a40d1..30bbd72 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -47,7 +47,6 @@ android {
 
 dependencies {
     implementation "com.google.android.material:material:$versions.googleMaterial"
-    implementation "androidx.constraintlayout:constraintlayout:$versions.constraintVersion"
     implementation "androidx.fragment:fragment-ktx:$versions.fragmentVersion"
 
     implementation "com.github.bumptech.glide:glide:$versions.glideVersion"
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/BindableApp.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/BindableApp.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/BindableApp.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/BindableApp.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/MainActivity.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/MainActivity.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/MainActivity.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/MainActivity.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/MainViewModel.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/MainViewModel.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/MainViewModel.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/MainViewModel.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/MockUtil.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/MockUtil.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/MockUtil.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/MockUtil.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/binding/RecyclerViewBinding.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/binding/RecyclerViewBinding.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/binding/RecyclerViewBinding.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/binding/RecyclerViewBinding.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/binding/ViewBinding.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/binding/ViewBinding.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/binding/ViewBinding.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/binding/ViewBinding.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/fragments/HomeFragment.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/fragments/HomeFragment.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/fragments/HomeFragment.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/fragments/HomeFragment.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/fragments/LibraryFragment.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/fragments/LibraryFragment.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/fragments/LibraryFragment.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/fragments/LibraryFragment.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/fragments/MainPagerAdapter.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/fragments/MainPagerAdapter.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/fragments/MainPagerAdapter.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/fragments/MainPagerAdapter.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/fragments/RadioFragment.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/fragments/RadioFragment.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/fragments/RadioFragment.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/fragments/RadioFragment.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/recycler/Poster.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/recycler/Poster.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/recycler/Poster.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/recycler/Poster.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/recycler/PosterAdapter.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/recycler/PosterAdapter.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/recycler/PosterAdapter.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/recycler/PosterAdapter.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/recycler/PosterCircleAdapter.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/recycler/PosterCircleAdapter.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/recycler/PosterCircleAdapter.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/recycler/PosterCircleAdapter.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/recycler/PosterDiffUtil.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/recycler/PosterDiffUtil.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/recycler/PosterDiffUtil.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/recycler/PosterDiffUtil.kt
diff --git a/app/src/main/java/com/skydoves/bindablesdemo/recycler/PosterLineAdapter.kt b/app/src/main/kotlin/com/skydoves/bindablesdemo/recycler/PosterLineAdapter.kt
similarity index 100%
rename from app/src/main/java/com/skydoves/bindablesdemo/recycler/PosterLineAdapter.kt
rename to app/src/main/kotlin/com/skydoves/bindablesdemo/recycler/PosterLineAdapter.kt
diff --git a/bindables/build.gradle b/bindables/build.gradle
index 7c5bac1..0415cf8 100644
--- a/bindables/build.gradle
+++ b/bindables/build.gradle
@@ -64,7 +64,6 @@ dependencies {
     implementation "androidx.appcompat:appcompat:$versions.androidxAppcompat"
     api "androidx.lifecycle:lifecycle-viewmodel-ktx:$versions.lifecycleVersion"
     api "androidx.lifecycle:lifecycle-viewmodel-savedstate:$versions.lifecycleVersion"
-    api "androidx.recyclerview:recyclerview:$versions.recyclerView"
 }
 
 apply plugin: "com.vanniktech.maven.publish"
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingActivity.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingActivity.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingActivity.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingActivity.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingBottomSheetDialogFragment.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingBottomSheetDialogFragment.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingBottomSheetDialogFragment.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingBottomSheetDialogFragment.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingComponentActivity.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingComponentActivity.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingComponentActivity.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingComponentActivity.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingDialogFragment.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingDialogFragment.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingDialogFragment.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingDialogFragment.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingExtensions.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingExtensions.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingExtensions.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingExtensions.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingFragment.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingFragment.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingFragment.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingFragment.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingFragmentActivity.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingFragmentActivity.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingFragmentActivity.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingFragmentActivity.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingInitProvider.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingInitProvider.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingInitProvider.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingInitProvider.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingListAdapter.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingListAdapter.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingListAdapter.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingListAdapter.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingManager.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingManager.kt
similarity index 88%
rename from bindables/src/main/java/com/skydoves/bindables/BindingManager.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingManager.kt
index 24ae6ce..8297e00 100644
--- a/bindables/src/main/java/com/skydoves/bindables/BindingManager.kt
+++ b/bindables/src/main/kotlin/com/skydoves/bindables/BindingManager.kt
@@ -73,11 +73,11 @@ public object BindingManager {
       it.getter.hasAnnotation<Bindable>()
     }
       ?: throw IllegalArgumentException("KProperty: ${property.name} must be annotated with the `@Bindable` annotation on the getter.")
-    val propertyName = bindingProperty.name.decapitalize(Locale.ENGLISH)
+    val propertyName = bindingProperty.name.replaceFirstChar { it.lowercase(Locale.ENGLISH) }
     val bindingPropertyName = propertyName
       .takeIf { it.startsWith(JAVA_BEANS_BOOLEAN) }
       ?.replaceFirst(JAVA_BEANS_BOOLEAN, String())
-      ?.decapitalize(Locale.ENGLISH) ?: propertyName
+      ?.replaceFirstChar { it.lowercase(Locale.ENGLISH) } ?: propertyName
     return bindingFieldsMap[bindingPropertyName] ?: BR._all
   }
 
@@ -91,13 +91,22 @@ public object BindingManager {
       it.hasAnnotation<Bindable>()
     }
       ?: throw IllegalArgumentException("KFunction: ${function.name} must be annotated with the `@Bindable` annotation.")
-    val functionName = bindingFunction.name.decapitalize(Locale.ENGLISH)
+    val functionName = bindingFunction.name.replaceFirstChar { it.lowercase(Locale.ENGLISH) }
     val bindingFunctionName = when {
-      functionName.startsWith(JAVA_BEANS_GETTER) -> functionName.replaceFirst(JAVA_BEANS_GETTER, String())
-      functionName.startsWith(JAVA_BEANS_SETTER) -> functionName.replaceFirst(JAVA_BEANS_SETTER, String())
-      functionName.startsWith(JAVA_BEANS_BOOLEAN) -> functionName.replaceFirst(JAVA_BEANS_BOOLEAN, String())
+      functionName.startsWith(JAVA_BEANS_GETTER) -> functionName.replaceFirst(
+        JAVA_BEANS_GETTER,
+        String()
+      )
+      functionName.startsWith(JAVA_BEANS_SETTER) -> functionName.replaceFirst(
+        JAVA_BEANS_SETTER,
+        String()
+      )
+      functionName.startsWith(JAVA_BEANS_BOOLEAN) -> functionName.replaceFirst(
+        JAVA_BEANS_BOOLEAN,
+        String()
+      )
       else -> throw IllegalArgumentException("@Bindable associated with method must follow JavaBeans convention $functionName")
-    }.decapitalize(Locale.ENGLISH)
+    }.replaceFirstChar { it.lowercase(Locale.ENGLISH) }
     return bindingFieldsMap[bindingFunctionName] ?: BR._all
   }
 }
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingModel.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingModel.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingModel.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingModel.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingObservable.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingObservable.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingObservable.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingObservable.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingOnly.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingOnly.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingOnly.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingOnly.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingProperty.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingProperty.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingProperty.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingProperty.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingPropertyDelegate.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingPropertyDelegate.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingPropertyDelegate.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingPropertyDelegate.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingRecyclerViewAdapter.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingRecyclerViewAdapter.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingRecyclerViewAdapter.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingRecyclerViewAdapter.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/BindingViewModel.kt b/bindables/src/main/kotlin/com/skydoves/bindables/BindingViewModel.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/BindingViewModel.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/BindingViewModel.kt
diff --git a/bindables/src/main/java/com/skydoves/bindables/FlowBindingProperty.kt b/bindables/src/main/kotlin/com/skydoves/bindables/FlowBindingProperty.kt
similarity index 100%
rename from bindables/src/main/java/com/skydoves/bindables/FlowBindingProperty.kt
rename to bindables/src/main/kotlin/com/skydoves/bindables/FlowBindingProperty.kt
diff --git a/dependencies.gradle b/dependencies.gradle
index 654fba5..e76f2c2 100644
--- a/dependencies.gradle
+++ b/dependencies.gradle
@@ -20,22 +20,20 @@ ext.versions = [
     versionName      : '1.0.9',
 
     gradleBuildTool  : '7.0.2',
-    spotlessGradle   : '5.15.0',
+    spotlessGradle   : '6.1.0',
     ktlintGradle     : '0.41.0',
     dokkaGradle      : '1.4.32',
     binaryValidator  : '0.7.1',
     mavenPublish     : '0.15.1',
 
-    kotlin           : '1.5.10',
-    androidxAppcompat: '1.4.0-alpha03',
+    kotlin           : '1.5.32',
+    androidxAppcompat: '1.4.0',
     googleMaterial   : '1.4.0',
-    lifecycleVersion : '2.3.1',
-    recyclerView     : '1.2.1',
+    lifecycleVersion : '2.4.0',
 
     // for demo
-    constraintVersion: '2.0.4',
     fragmentVersion  : '1.2.5',
-    hiltCoreVersion  : '2.38.1',
+    hiltCoreVersion  : '2.40.5',
     hiltVersion      : '1.0.0',
     glideVersion     : '4.12.0',
     whatIfVersion    : '1.1.0',