diff --git a/cmd/mttilemapper/main.go b/cmd/mttilemapper/main.go
index cf72ad1..e129524 100644
--- a/cmd/mttilemapper/main.go
+++ b/cmd/mttilemapper/main.go
@@ -123,7 +123,7 @@ func main() {
 			c1.Y = q1y
 		}
 		cuboid := common.Cuboid{P1: common.MinCoord(c1, c2), P2: common.MaxCoord(c1, c2)}
-		if err = client.QueryCuboid(cuboid, drawBlock); err != nil {
+		if _, err = client.QueryCuboid(cuboid, drawBlock); err != nil {
 			log.Fatalf("query failed: %s", err)
 		}
 		if err = yOrder.Drain(colors); err != nil {