diff --git a/libs/gui/SurfaceControl.cpp b/libs/gui/SurfaceControl.cpp
index 61011b9..1983027 100644
--- a/libs/gui/SurfaceControl.cpp
+++ b/libs/gui/SurfaceControl.cpp
@@ -89,12 +89,12 @@
     return lhs->mHandle == rhs->mHandle;
 }
 
-status_t SurfaceControl::setLayerStack(int32_t layerStack) {
+status_t SurfaceControl::setLayerStack(uint32_t layerStack) {
     status_t err = validate();
     if (err < 0) return err;
     return mClient->setLayerStack(mHandle, layerStack);
 }
-status_t SurfaceControl::setLayer(int32_t layer) {
+status_t SurfaceControl::setLayer(uint32_t layer) {
     status_t err = validate();
     if (err < 0) return err;
     return mClient->setLayer(mHandle, layer);