diff --git a/build.gradle b/build.gradle
index ea6e358..3f12d79 100644
--- a/build.gradle
+++ b/build.gradle
@@ -3,10 +3,11 @@
 buildscript {
     repositories {
         jcenter()
+        google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.0.0'
-        classpath 'com.novoda:bintray-release:0.3.4'
+        classpath 'com.android.tools.build:gradle:3.0.1'
+        classpath 'com.novoda:bintray-release:0.8.0'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$KOTLIN_VERSION"
     }
 }
@@ -14,5 +15,6 @@ buildscript {
 allprojects {
     repositories {
         jcenter()
+        google()
     }
 }
diff --git a/gradle.properties b/gradle.properties
index 562d758..443fc55 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,15 +1,14 @@
-COMPILE_SDK_VERSION=23
-BUILD_TOOLS_VERSION=22.0.1
-MIN_SDK_VERSION=11
-TARGET_SDK_VERSION=23
+COMPILE_SDK_VERSION=27
+MIN_SDK_VERSION=14
+TARGET_SDK_VERSION=27
 VERSION_CODE=11
 VERSION_NAME=1.6.0
 SUPPORT_TEST_VERSION=0.4.1
 HAMCREST_VERSION=1.3
 ESPRESSO_VERSION=2.2.1
-KOTLIN_VERSION=1.0.0
+KOTLIN_VERSION=1.2.10
 
-SUPPORT_APP_COMPAT_VERSION=23.2.1
+SUPPORT_APP_COMPAT_VERSION=27.0.2
 
 GROUP=com.github.aakira
 ARTIFACT_ID=expandable-layout
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 54a566d..ab94511 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Fri Apr 08 10:39:51 JST 2016
+#Thu Dec 14 18:32:57 CET 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.10-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip
diff --git a/library-ui-test/build.gradle b/library-ui-test/build.gradle
index 5b27b4d..5c92a74 100644
--- a/library-ui-test/build.gradle
+++ b/library-ui-test/build.gradle
@@ -3,7 +3,6 @@ apply plugin: 'kotlin-android'
 
 android {
     compileSdkVersion COMPILE_SDK_VERSION as int
-    buildToolsVersion BUILD_TOOLS_VERSION
 
     defaultConfig {
         minSdkVersion MIN_SDK_VERSION as int
diff --git a/library/build.gradle b/library/build.gradle
index bc43d51..39cc086 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -3,7 +3,6 @@ apply plugin: 'com.novoda.bintray-release'
 
 android {
     compileSdkVersion COMPILE_SDK_VERSION as int
-    buildToolsVersion BUILD_TOOLS_VERSION
 
     defaultConfig {
         minSdkVersion MIN_SDK_VERSION as int
diff --git a/sample/build.gradle b/sample/build.gradle
index 8604cea..ee9872f 100644
--- a/sample/build.gradle
+++ b/sample/build.gradle
@@ -2,7 +2,6 @@ apply plugin: 'com.android.application'
 
 android {
     compileSdkVersion COMPILE_SDK_VERSION as int
-    buildToolsVersion BUILD_TOOLS_VERSION
 
     defaultConfig {
         minSdkVersion MIN_SDK_VERSION as int