diff --git a/mobile/android/base/gfx/GeckoLayerClient.java b/mobile/android/base/gfx/GeckoLayerClient.java
index 6167f1523fea..8ff83f9331dc 100644
--- a/mobile/android/base/gfx/GeckoLayerClient.java
+++ b/mobile/android/base/gfx/GeckoLayerClient.java
@@ -357,7 +357,7 @@ public class GeckoLayerClient implements LayerView.Listener, PanZoomTarget
 
     /** Viewport message handler. */
     private DisplayPortMetrics handleViewportMessage(ImmutableViewportMetrics messageMetrics, ViewportMessageType type) {
-        synchronized (this) {
+        synchronized (getLock()) {
             ImmutableViewportMetrics newMetrics;
             ImmutableViewportMetrics oldMetrics = getViewportMetrics();
 
@@ -531,7 +531,7 @@ public class GeckoLayerClient implements LayerView.Listener, PanZoomTarget
     public void setFirstPaintViewport(float offsetX, float offsetY, float zoom,
             float pageLeft, float pageTop, float pageRight, float pageBottom,
             float cssPageLeft, float cssPageTop, float cssPageRight, float cssPageBottom) {
-        synchronized (this) {
+        synchronized (getLock()) {
             ImmutableViewportMetrics currentMetrics = getViewportMetrics();
 
             Tab tab = Tabs.getInstance().getSelectedTab();
@@ -584,7 +584,7 @@ public class GeckoLayerClient implements LayerView.Listener, PanZoomTarget
       * function will be invoked before syncViewportInfo.
       */
     public void setPageRect(float cssPageLeft, float cssPageTop, float cssPageRight, float cssPageBottom) {
-        synchronized (this) {
+        synchronized (getLock()) {
             RectF cssPageRect = new RectF(cssPageLeft, cssPageTop, cssPageRight, cssPageBottom);
             float ourZoom = getViewportMetrics().zoomFactor;
             setPageRect(RectUtils.scale(cssPageRect, ourZoom), cssPageRect);