diff --git a/.travis.yml b/.travis.yml
index d4d777361..d3ff65b1b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,9 +4,9 @@ android:
   components:
     - tools
     - platform-tools
-    - build-tools-26.0.3
-    - android-26
-    - extra-android-m2repository
+    - tools
+    - build-tools-27.0.2
+    - android-27
 
 jdk:
   - oraclejdk8
diff --git a/build.gradle b/build.gradle
index 1b3688860..7a940b9f1 100644
--- a/build.gradle
+++ b/build.gradle
@@ -16,6 +16,11 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
+    ext.versions = [
+        'androidSdk' : 27,
+        'buildTools': '27.0.2',
+        'supportLibrary': '27.0.2',
+    ]
     repositories {
         jcenter()
         google()
diff --git a/checkstyle.xml b/checkstyle.xml
index a3424dd75..ff1c021e7 100644
--- a/checkstyle.xml
+++ b/checkstyle.xml
@@ -136,7 +136,6 @@
         <module name="InnerAssignment"/>
         <!--<module name="MagicNumber"/>-->
         <module name="MissingSwitchDefault"/>
-        <module name="RedundantThrows"/>
         <module name="SimplifyBooleanExpression"/>
         <module name="SimplifyBooleanReturn"/>
 
diff --git a/matisse/build.gradle b/matisse/build.gradle
index 4ce317316..418f18278 100644
--- a/matisse/build.gradle
+++ b/matisse/build.gradle
@@ -18,12 +18,12 @@ apply plugin: 'com.novoda.bintray-release'
 apply plugin: 'checkstyle'
 
 android {
-    compileSdkVersion 26
-    buildToolsVersion "26.0.3"
+    compileSdkVersion versions.androidSdk
+    buildToolsVersion versions.buildTools
 
     defaultConfig {
         minSdkVersion 14
-        targetSdkVersion 26
+        targetSdkVersion versions.androidSdk
     }
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_7
@@ -34,15 +34,13 @@ android {
     }
 }
 
-ext.supportLibVersion = '26.1.0'
-
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
 
-    implementation "com.android.support:support-v4:${supportLibVersion}"
-    implementation "com.android.support:appcompat-v7:${supportLibVersion}"
-    implementation "com.android.support:support-annotations:${supportLibVersion}"
-    implementation "com.android.support:recyclerview-v7:${supportLibVersion}"
+    implementation "com.android.support:support-v4:${versions.supportLibrary}"
+    implementation "com.android.support:appcompat-v7:${versions.supportLibrary}"
+    implementation "com.android.support:support-annotations:${versions.supportLibrary}"
+    implementation "com.android.support:recyclerview-v7:${versions.supportLibrary}"
     implementation 'it.sephiroth.android.library.imagezoom:library:1.0.4'
 
     compileOnly 'com.github.bumptech.glide:glide:3.7.0'
@@ -68,4 +66,4 @@ task checkstyle(type:Checkstyle) {
     showViolations true
     classpath = files()
     source 'src/main/java'
-}
\ No newline at end of file
+}
diff --git a/sample/build.gradle b/sample/build.gradle
index fddf353c7..1dce1ed5c 100644
--- a/sample/build.gradle
+++ b/sample/build.gradle
@@ -16,13 +16,13 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 26
-    buildToolsVersion "26.0.3"
+    compileSdkVersion versions.androidSdk
+    buildToolsVersion versions.buildTools
 
     defaultConfig {
         applicationId 'com.zhihu.matisse.sample'
         minSdkVersion 14
-        targetSdkVersion 26
+        targetSdkVersion versions.androidSdk
         versionCode 1
         versionName "1.0"
     }
@@ -35,16 +35,14 @@ android {
     }
 }
 
-ext.supportLibVersion = '26.1.0'
-
 dependencies {
     implementation project(':matisse')
     implementation fileTree(dir: 'libs', include: ['*.jar'])
 
-    implementation "com.android.support:appcompat-v7:${supportLibVersion}"
-    implementation "com.android.support:recyclerview-v7:${supportLibVersion}"
-    implementation 'com.tbruyelle.rxpermissions2:rxpermissions:0.9.1@aar'
-    implementation 'io.reactivex.rxjava2:rxjava:2.0.5'
+    implementation "com.android.support:appcompat-v7:${versions.supportLibrary}"
+    implementation "com.android.support:recyclerview-v7:${versions.supportLibrary}"
+    implementation 'com.tbruyelle.rxpermissions2:rxpermissions:0.9.2@aar'
+    implementation 'io.reactivex.rxjava2:rxjava:2.1.7'
     implementation 'com.github.bumptech.glide:glide:3.7.0'
     implementation 'com.squareup.picasso:picasso:2.5.2'
 }