diff --git a/libs/gui/ISurfaceComposer.cpp b/libs/gui/ISurfaceComposer.cpp
index fa2f59a..74c3bed 100644
--- a/libs/gui/ISurfaceComposer.cpp
+++ b/libs/gui/ISurfaceComposer.cpp
@@ -104,7 +104,7 @@
     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,
             ISurfaceComposer::Rotation rotation)
     {
@@ -115,8 +115,8 @@
         data.write(sourceCrop);
         data.writeUint32(reqWidth);
         data.writeUint32(reqHeight);
-        data.writeUint32(minLayerZ);
-        data.writeUint32(maxLayerZ);
+        data.writeInt32(minLayerZ);
+        data.writeInt32(maxLayerZ);
         data.writeInt32(static_cast<int32_t>(useIdentityTransform));
         data.writeInt32(static_cast<int32_t>(rotation));
         remote()->transact(BnSurfaceComposer::CAPTURE_SCREEN, data, &reply);
@@ -544,8 +544,8 @@
             data.read(sourceCrop);
             uint32_t reqWidth = data.readUint32();
             uint32_t reqHeight = data.readUint32();
-            uint32_t minLayerZ = data.readUint32();
-            uint32_t maxLayerZ = data.readUint32();
+            int32_t minLayerZ = data.readInt32();
+            int32_t maxLayerZ = data.readInt32();
             bool useIdentityTransform = static_cast<bool>(data.readInt32());
             int32_t rotation = data.readInt32();
 
diff --git a/libs/gui/LayerState.cpp b/libs/gui/LayerState.cpp
index 3949186..16bf324 100644
--- a/libs/gui/LayerState.cpp
+++ b/libs/gui/LayerState.cpp
@@ -28,7 +28,7 @@
     output.writeUint32(what);
     output.writeFloat(x);
     output.writeFloat(y);
-    output.writeUint32(z);
+    output.writeInt32(z);
     output.writeUint32(w);
     output.writeUint32(h);
     output.writeUint32(layerStack);
@@ -54,7 +54,7 @@
     what = input.readUint32();
     x = input.readFloat();
     y = input.readFloat();
-    z = input.readUint32();
+    z = input.readInt32();
     w = input.readUint32();
     h = input.readUint32();
     layerStack = input.readUint32();
diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index 3346a83..540dbd9 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -148,7 +148,7 @@
     status_t setSize(const sp<SurfaceComposerClient>& client, const sp<IBinder>& id,
             uint32_t w, uint32_t h);
     status_t setLayer(const sp<SurfaceComposerClient>& client, const sp<IBinder>& id,
-            uint32_t z);
+            int32_t z);
     status_t setLayerInfo(const sp<SurfaceComposerClient>& client, const sp<IBinder>& id,
             uint32_t type, uint32_t appid);
     status_t setFlags(const sp<SurfaceComposerClient>& client, const sp<IBinder>& id,
@@ -327,7 +327,7 @@
 }
 
 status_t Composer::setLayer(const sp<SurfaceComposerClient>& client,
-        const sp<IBinder>& id, uint32_t z) {
+        const sp<IBinder>& id, int32_t z) {
     Mutex::Autolock _l(mLock);
     layer_state_t* s = getLayerStateLocked(client, id);
     if (!s)
@@ -714,7 +714,7 @@
     return getComposer().setSize(this, id, w, h);
 }
 
-status_t SurfaceComposerClient::setLayer(const sp<IBinder>& id, uint32_t z) {
+status_t SurfaceComposerClient::setLayer(const sp<IBinder>& id, int32_t z) {
     return getComposer().setLayer(this, id, z);
 }
 
@@ -871,7 +871,7 @@
         const sp<IBinder>& display,
         const sp<IGraphicBufferProducer>& producer,
         Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-        uint32_t minLayerZ, uint32_t maxLayerZ, bool useIdentityTransform) {
+        int32_t minLayerZ, int32_t maxLayerZ, bool useIdentityTransform) {
     sp<ISurfaceComposer> s(ComposerService::getComposerService());
     if (s == NULL) return NO_INIT;
     return s->captureScreen(display, producer, sourceCrop,
@@ -880,7 +880,7 @@
 
 status_t ScreenshotClient::captureToBuffer(const sp<IBinder>& display,
         Rect sourceCrop, uint32_t reqWidth, uint32_t reqHeight,
-        uint32_t minLayerZ, uint32_t maxLayerZ, bool useIdentityTransform,
+        int32_t minLayerZ, int32_t maxLayerZ, bool useIdentityTransform,
         uint32_t rotation,
         sp<GraphicBuffer>* outBuffer) {
     sp<ISurfaceComposer> s(ComposerService::getComposerService());
@@ -926,7 +926,7 @@
 
 status_t ScreenshotClient::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<ISurfaceComposer> s(ComposerService::getComposerService());
     if (s == NULL) return NO_INIT;
@@ -953,7 +953,7 @@
 
 status_t ScreenshotClient::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) {
 
     return ScreenshotClient::update(display, sourceCrop, reqWidth, reqHeight,
@@ -962,14 +962,16 @@
 
 status_t ScreenshotClient::update(const sp<IBinder>& display, Rect sourceCrop,
         bool useIdentityTransform) {
-    return ScreenshotClient::update(display, sourceCrop, 0, 0, 0, -1U,
+    return ScreenshotClient::update(display, sourceCrop, 0, 0,
+            INT32_MIN, INT32_MAX,
             useIdentityTransform, ISurfaceComposer::eRotateNone);
 }
 
 status_t ScreenshotClient::update(const sp<IBinder>& display, Rect sourceCrop,
         uint32_t reqWidth, uint32_t reqHeight, bool useIdentityTransform) {
     return ScreenshotClient::update(display, sourceCrop, reqWidth, reqHeight,
-            0, -1U, useIdentityTransform, ISurfaceComposer::eRotateNone);
+            INT32_MIN, INT32_MAX,
+            useIdentityTransform, ISurfaceComposer::eRotateNone);
 }
 
 void ScreenshotClient::release() {
diff --git a/libs/gui/SurfaceControl.cpp b/libs/gui/SurfaceControl.cpp
index b47e434..c82f6a7 100644
--- a/libs/gui/SurfaceControl.cpp
+++ b/libs/gui/SurfaceControl.cpp
@@ -102,7 +102,7 @@
     if (err < 0) return err;
     return mClient->setLayerStack(mHandle, layerStack);
 }
-status_t SurfaceControl::setLayer(uint32_t layer) {
+status_t SurfaceControl::setLayer(int32_t layer) {
     status_t err = validate();
     if (err < 0) return err;
     return mClient->setLayer(mHandle, layer);
diff --git a/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index e40b4eb..7b78175 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -398,7 +398,7 @@
     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*/) override { return NO_ERROR; }
     status_t clearAnimationFrameStats() override { return NO_ERROR; }