diff --git a/app/build.gradle b/app/build.gradle
index 3d88cc0..62fc7a3 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -1,12 +1,12 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion "25.0.2"
+    compileSdkVersion 27
+    buildToolsVersion '27.0.3'
     defaultConfig {
         applicationId "jp.shts.android.storyprogressbar"
         minSdkVersion 15
-        targetSdkVersion 25
+        targetSdkVersion 27
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -20,12 +20,11 @@ android {
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
+    implementation project(':library')
+    implementation 'com.android.support:appcompat-v7:27.1.1'
+    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation('com.android.support.test.espresso:espresso-core:2.2.2', {
         exclude group: 'com.android.support', module: 'support-annotations'
     })
-    compile 'com.android.support:appcompat-v7:25.3.1'
-    compile 'com.android.support.constraint:constraint-layout:1.0.2'
-    testCompile 'junit:junit:4.12'
-    compile project(':library')
 }
diff --git a/build.gradle b/build.gradle
index 25973c5..767da9a 100644
--- a/build.gradle
+++ b/build.gradle
@@ -4,9 +4,10 @@ buildscript {
     repositories {
         jcenter()
         mavenCentral()
+        google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.1'
+        classpath 'com.android.tools.build:gradle:3.1.4'
         classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -16,6 +17,7 @@ buildscript {
 allprojects {
     repositories {
         jcenter()
+        google()
     }
 }
 
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 34a1d4a..74cc99b 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Thu Jul 20 16:57:17 JST 2017
+#Mon Sep 10 10:57:05 WEST 2018
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-all.zip
diff --git a/library/build.gradle b/library/build.gradle
index dccf509..79e87bc 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -1,12 +1,12 @@
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion "25.0.2"
+    compileSdkVersion 27
+    buildToolsVersion '27.0.3'
 
     defaultConfig {
         minSdkVersion 15
-        targetSdkVersion 25
+        targetSdkVersion 27
         versionCode 1
         versionName "1.0"
 
@@ -22,10 +22,9 @@ android {
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
-    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
+    implementation 'com.android.support:appcompat-v7:27.1.1'
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation('com.android.support.test.espresso:espresso-core:2.2.2', {
         exclude group: 'com.android.support', module: 'support-annotations'
     })
-    compile 'com.android.support:appcompat-v7:25.3.1'
-    testCompile 'junit:junit:4.12'
 }