diff --git a/apps/plugins/lib/grey_draw.c b/apps/plugins/lib/grey_draw.c
index 2ae96603df..286cae06a4 100644
--- a/apps/plugins/lib/grey_draw.c
+++ b/apps/plugins/lib/grey_draw.c
@@ -673,7 +673,7 @@ static void output_row_grey(uint32_t row, void * row_in, struct scaler_context *
     uint32_t *qp = (uint32_t*)row_in;
     uint8_t *dest = (uint8_t*)ctx->bm->data + ctx->bm->width * row;
     for (col = 0; col < ctx->bm->width; col++)
-        *dest++ = ((*qp++) + ctx->round) * (uint64_t)ctx->divisor >> 32;
+        *dest++ = SC_MUL((*qp++) + ctx->round,ctx->divisor);
 }
 
 static unsigned int get_size_grey(struct bitmap *bm)