diff --git a/visionSamples/multi-tracker/app/build.gradle b/visionSamples/multi-tracker/app/build.gradle
index 101cf88a..091155c2 100644
--- a/visionSamples/multi-tracker/app/build.gradle
+++ b/visionSamples/multi-tracker/app/build.gradle
@@ -22,6 +22,6 @@ android {
 dependencies {
     compile fileTree(dir: 'libs', include: ['*.jar'])
     compile 'com.android.support:support-v4:23+'
-    compile 'com.google.android.gms:play-services:7.8.+'
+    compile 'com.google.android.gms:play-services:8.4.+'
     compile 'com.android.support:design:23.0.0'
-}
\ No newline at end of file
+}
diff --git a/visionSamples/multi-tracker/app/src/main/java/com/google/android/gms/samples/vision/face/multitracker/MultiTrackerActivity.java b/visionSamples/multi-tracker/app/src/main/java/com/google/android/gms/samples/vision/face/multitracker/MultiTrackerActivity.java
index ed85fd8b..b17c641f 100644
--- a/visionSamples/multi-tracker/app/src/main/java/com/google/android/gms/samples/vision/face/multitracker/MultiTrackerActivity.java
+++ b/visionSamples/multi-tracker/app/src/main/java/com/google/android/gms/samples/vision/face/multitracker/MultiTrackerActivity.java
@@ -185,6 +185,7 @@ private void createCameraSource() {
                 .setFacing(CameraSource.CAMERA_FACING_BACK)
                 .setRequestedPreviewSize(1600, 1024)
                 .setRequestedFps(15.0f)
+                .setAutoFocusEnabled(true)
                 .build();
     }