diff --git a/libcopybit/copybit.cpp b/libcopybit/copybit.cpp
index 42378ea..1b3436b 100644
--- a/libcopybit/copybit.cpp
+++ b/libcopybit/copybit.cpp
@@ -285,7 +285,7 @@ static int set_parameter_copybit(
             }
             break;
         case COPYBIT_PLANE_ALPHA:
-            if (value < 0)      value = 0;
+            if (value < 0)      value = MDP_ALPHA_NOP;
             if (value >= 256)   value = 255;
             ctx->mAlpha = value;
             break;
diff --git a/libhwcomposer/hwcomposer.cpp b/libhwcomposer/hwcomposer.cpp
index e261911..822d64e 100755
--- a/libhwcomposer/hwcomposer.cpp
+++ b/libhwcomposer/hwcomposer.cpp
@@ -1069,7 +1069,7 @@ static int drawLayerUsingCopybit(hwc_composer_device_t *dev, hwc_layer_t *layer,
     copybit->set_parameter(copybit, COPYBIT_FRAMEBUFFER_HEIGHT, renderBuffer->height);
     copybit->set_parameter(copybit, COPYBIT_TRANSFORM, layer->transform);
     copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA,
-                           (layer->blending == HWC_BLENDING_NONE) ? 0x0 : layer->alpha);
+                           (layer->blending == HWC_BLENDING_NONE) ? -1 : layer->alpha);
     copybit->set_parameter(copybit, COPYBIT_PREMULTIPLIED_ALPHA,
                            (layer->blending == HWC_BLENDING_PREMULT)? COPYBIT_ENABLE : COPYBIT_DISABLE);
     err = copybit->stretch(copybit, &dst, &src, &dstRect, &srcRect, &copybitRegion);