diff --git a/app/build.gradle b/app/build.gradle
index 17a0186..4d3f5d2 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -1,12 +1,12 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 26
-    buildToolsVersion "26.0.2"
+    compileSdkVersion 28
+    buildToolsVersion "28.0.2"
     defaultConfig {
         applicationId "tellh.com.recyclertreeview"
-        minSdkVersion 14
-        targetSdkVersion 26
+        minSdkVersion 21
+        targetSdkVersion 28
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -24,8 +24,8 @@ dependencies {
     androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
         exclude group: 'com.android.support', module: 'support-annotations'
     })
-    compile 'com.android.support:appcompat-v7:26.1.0'
-    compile 'com.android.support:recyclerview-v7:26.1.0'
+    compile 'com.android.support:appcompat-v7:28.0.0'
+    compile 'com.android.support:recyclerview-v7:28.0.0'
     testCompile 'junit:junit:4.12'
     compile project(path: ':recyclertreeview-lib')
 //    compile 'com.github.TellH:RecyclerTreeView:1.2.0'