diff --git a/protos/stationLayoutGraphics.proto b/protos/stationLayoutGraphics.proto
index 59658dd..206395c 100644
--- a/protos/stationLayoutGraphics.proto
+++ b/protos/stationLayoutGraphics.proto
@@ -143,6 +143,7 @@ message Turnout {
 message Signal {
   CommonInfo common = 1;
   string code = 2;
+  bool mirror = 3;
 }
 
 message RunLine {