diff --git a/src/com/android/settings/inputmethod/TouchpadReverseScrollingPreferenceController.java b/src/com/android/settings/inputmethod/TouchpadReverseScrollingPreferenceController.java
index dfd763499f3..46fc576fc3a 100644
--- a/src/com/android/settings/inputmethod/TouchpadReverseScrollingPreferenceController.java
+++ b/src/com/android/settings/inputmethod/TouchpadReverseScrollingPreferenceController.java
@@ -27,7 +27,7 @@ import com.android.settingslib.core.instrumentation.MetricsFeatureProvider;
 
 public class TouchpadReverseScrollingPreferenceController extends TogglePreferenceController {
 
-    private MetricsFeatureProvider mMetricsFeatureProvider;
+    private final MetricsFeatureProvider mMetricsFeatureProvider;
 
     public TouchpadReverseScrollingPreferenceController(Context context, String key) {
         super(context, key);
diff --git a/src/com/android/settings/inputmethod/TouchpadRightClickZonePreferenceController.java b/src/com/android/settings/inputmethod/TouchpadRightClickZonePreferenceController.java
index f98812d563b..77b0b491844 100644
--- a/src/com/android/settings/inputmethod/TouchpadRightClickZonePreferenceController.java
+++ b/src/com/android/settings/inputmethod/TouchpadRightClickZonePreferenceController.java
@@ -27,7 +27,7 @@ import com.android.settingslib.core.instrumentation.MetricsFeatureProvider;
 
 public class TouchpadRightClickZonePreferenceController extends TogglePreferenceController {
 
-    private MetricsFeatureProvider mMetricsFeatureProvider;
+    private final MetricsFeatureProvider mMetricsFeatureProvider;
 
     public TouchpadRightClickZonePreferenceController(Context context, String key) {
         super(context, key);
diff --git a/src/com/android/settings/inputmethod/TouchpadTapDraggingPreferenceController.java b/src/com/android/settings/inputmethod/TouchpadTapDraggingPreferenceController.java
index 59cf85d5a3a..12d426f45c0 100644
--- a/src/com/android/settings/inputmethod/TouchpadTapDraggingPreferenceController.java
+++ b/src/com/android/settings/inputmethod/TouchpadTapDraggingPreferenceController.java
@@ -27,7 +27,7 @@ import com.android.settingslib.core.instrumentation.MetricsFeatureProvider;
 
 public class TouchpadTapDraggingPreferenceController extends TogglePreferenceController {
 
-    private MetricsFeatureProvider mMetricsFeatureProvider;
+    private final MetricsFeatureProvider mMetricsFeatureProvider;
 
     public TouchpadTapDraggingPreferenceController(Context context, String key) {
         super(context, key);
diff --git a/src/com/android/settings/inputmethod/TouchpadTapToClickPreferenceController.java b/src/com/android/settings/inputmethod/TouchpadTapToClickPreferenceController.java
index 4b9aa1f2ea3..54b34fdf921 100644
--- a/src/com/android/settings/inputmethod/TouchpadTapToClickPreferenceController.java
+++ b/src/com/android/settings/inputmethod/TouchpadTapToClickPreferenceController.java
@@ -27,7 +27,7 @@ import com.android.settingslib.core.instrumentation.MetricsFeatureProvider;
 
 public class TouchpadTapToClickPreferenceController extends TogglePreferenceController {
 
-    private MetricsFeatureProvider mMetricsFeatureProvider;
+    private final MetricsFeatureProvider mMetricsFeatureProvider;
 
     public TouchpadTapToClickPreferenceController(Context context, String key) {
         super(context, key);