diff --git a/include/gui/ISurfaceComposer.h b/include/gui/ISurfaceComposer.h
index 824e5c4..ff04e2f 100644
--- a/include/gui/ISurfaceComposer.h
+++ b/include/gui/ISurfaceComposer.h
@@ -157,7 +157,7 @@
     virtual status_t captureScreen(const sp<IBinder>& display,
             const sp<IGraphicBufferProducer>& producer,
             Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-            uint32_t minLayerZ, uint32_t maxLayerZ,
+            int32_t minLayerZ, int32_t maxLayerZ,
             bool useIdentityTransform,
             Rotation rotation = eRotateNone) = 0;
 
diff --git a/include/gui/SurfaceComposerClient.h b/include/gui/SurfaceComposerClient.h
index 183b42d..4356a58 100644
--- a/include/gui/SurfaceComposerClient.h
+++ b/include/gui/SurfaceComposerClient.h
@@ -142,7 +142,7 @@
     status_t    show(const sp<IBinder>& id);
     status_t    setFlags(const sp<IBinder>& id, uint32_t flags, uint32_t mask);
     status_t    setTransparentRegionHint(const sp<IBinder>& id, const Region& transparent);
-    status_t    setLayer(const sp<IBinder>& id, uint32_t layer);
+    status_t    setLayer(const sp<IBinder>& id, int32_t layer);
     status_t    setLayerInfo(const sp<IBinder>& id, uint32_t type, uint32_t appid);
     status_t    setAlpha(const sp<IBinder>& id, float alpha=1.0f);
     status_t    setMatrix(const sp<IBinder>& id, float dsdx, float dtdx, float dsdy, float dtdy);
@@ -213,12 +213,12 @@
             const sp<IBinder>& display,
             const sp<IGraphicBufferProducer>& producer,
             Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-            uint32_t minLayerZ, uint32_t maxLayerZ,
+            int32_t minLayerZ, int32_t maxLayerZ,
             bool useIdentityTransform);
     static status_t captureToBuffer(
             const sp<IBinder>& display,
             Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-            uint32_t minLayerZ, uint32_t maxLayerZ,
+            int32_t minLayerZ, int32_t maxLayerZ,
             bool useIdentityTransform,
             uint32_t rotation,
             sp<GraphicBuffer>* outbuffer);
@@ -242,11 +242,11 @@
             bool useIdentityTransform);
     status_t update(const sp<IBinder>& display,
             Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-            uint32_t minLayerZ, uint32_t maxLayerZ,
+            int32_t minLayerZ, int32_t maxLayerZ,
             bool useIdentityTransform);
     status_t update(const sp<IBinder>& display,
             Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-            uint32_t minLayerZ, uint32_t maxLayerZ,
+            int32_t minLayerZ, int32_t maxLayerZ,
             bool useIdentityTransform, uint32_t rotation);
 
     sp<CpuConsumer> getCpuConsumer() const;
diff --git a/include/gui/SurfaceControl.h b/include/gui/SurfaceControl.h
index 456bde4..62217ad 100644
--- a/include/gui/SurfaceControl.h
+++ b/include/gui/SurfaceControl.h
@@ -61,7 +61,7 @@
     void        disconnect();
 
     status_t    setLayerStack(uint32_t layerStack);
-    status_t    setLayer(uint32_t layer);
+    status_t    setLayer(int32_t layer);
     status_t    setLayerInfo(uint32_t type, uint32_t appid);
     status_t    setPosition(float x, float y);
     status_t    setSize(uint32_t w, uint32_t h);