diff --git a/.travis.yml b/.travis.yml
index d1802e11..d312497b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,19 +3,15 @@ scala:
 - 2.10.4
 before_install:
 - sudo apt-get update
-- sudo apt-get install libc6-dev-i386
-- sudo apt-get install lib32ncurses5-dev
-- sudo apt-get install libx11-dev
-- sudo apt-get install g++-multilib
-- sudo apt-get install lib32z1-dev
-- sudo apt-get install ccache
+install:
+- sudo apt-get install -y libc6-dev-i386 lib32ncurses5-dev libx11-dev g++-multilib lib32z1-dev ccache
 - export NDK_CCACHE=ccache
 - export ARCH=`uname -m`
 - wget http://dl.google.com/android/android-sdk_r23.0.2-linux.tgz
 - tar xf android-sdk_r23.0.2-linux.tgz
 - wget http://dl.google.com/android/ndk/android-ndk-r9d-linux-${ARCH}.tar.bz2
 - tar xf android-ndk-r9d-linux-${ARCH}.tar.bz2
-- export ANDROID_NDK=`pwd`/android-ndk-r9d
+- export ANDROID_NDK_HOME=`pwd`/android-ndk-r9d
 - export ANDROID_HOME=`pwd`/android-sdk-linux
 - export PATH=${PATH}:${ANDROID_NDK_HOME}:${ANDROID_HOME}/tools:${ANDROID_HOME}/platform-tools
 - echo "y" | android update sdk --filter tools,platform-tools,build-tools-21.0.1,android-21,extra-google-m2repository --no-ui --no-https -a
diff --git a/README.md b/README.md
index 505867a3..6b54db77 100644
--- a/README.md
+++ b/README.md
@@ -39,7 +39,7 @@ Help to translate shadowsocks: http://crowdin.net/project/shadowsocks/invite
 #### BUILD on Mac OS X (with HomeBrew)
 
 * Install Android SDK and NDK by run `brew install android-ndk android-sdk`
-* Add `export ANDROID_HOME=/usr/local/Cellar/android-sdk/$version` to your .bashrc , then reopen the shell to loat it.
+* Add `export ANDROID_HOME=/usr/local/Cellar/android-sdk/$version` to your .bashrc , then reopen the shell to load it.
 * Run `echo "y" | android update sdk --filter tools,platform-tools,build-tools-19.0.3,android-19,extra-google-m2repository,extra-android-m2repository --no-ui --no-https -a`
 * Create your key following the instructions at http://developer.android.com/guide/publishing/app-signing.html#cert
 * Put your key in ~/.keystore
diff --git a/build-ndk.sh b/build-ndk.sh
index 4f22cc2a..0aa162f5 100755
--- a/build-ndk.sh
+++ b/build-ndk.sh
@@ -5,8 +5,8 @@ function try () {
 }
 
 # Build
-try ndk-build clean
-try ndk-build
+try $ANDROID_NDK_HOME/ndk-build clean
+try $ANDROID_NDK_HOME/ndk-build
 
 # copy executables
 rm -rf src/main/assets/armeabi-v7a