diff --git a/protos/MapInfoProto.proto b/protos/MapInfoProto.proto
index 276755f..f3095d6 100644
--- a/protos/MapInfoProto.proto
+++ b/protos/MapInfoProto.proto
@@ -268,4 +268,7 @@ import "CommonProto.proto";
 	message SignEndlessCellRequest{
 		optional endlessSign sign = 1;
 	}
+	message SignEndlessCellResponse{
+		optional string error = 1;
+	}