I have this error :

```
Execution failed for task ':app:packageAllDebugClassesForMultiDex'.
> java.util.zip.ZipException: duplicate entry: com/google/android/gms/internal/zzrf.class

```

I want to add google play services to my project so i put this line in build.gradle file :

```
compile 'com.google.android.gms:play-services:7.8.0'

```

So I had to enable multidex and I followed android doc, adding this in build.gradle : 

```
compile 'com.android.support:multidex:1.0.1'

```

and

```
multiDexEnabled true

```

I add this in android manifest :

```
<application 
...
android:name="android.support.multidex.MultiDexApplication">

```

But I have the error I wrote above. I've found a lot of questions relative to this problem (app:packageAllDebugClassesForMultiDex) but not with that (duplicate entry: com/google/android/gms/internal/zzrf.class).

I tried some solutions like remove some google libraries but I don't know what refers to internal/zzrf.class.

Here is my gradle file :

```
apply plugin: 'com.android.application'

android {
    compileSdkVersion 22
    buildToolsVersion "22.0.1"

    defaultConfig {
        applicationId "fr.djey.testgoogleplus"
        minSdkVersion 16
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
        multiDexEnabled true
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:22.2.1'
    compile 'com.google.android.gms:play-services:7.8.0'
    compile 'com.android.support:multidex:1.0.1'
}

```