diff --git a/src/tunnelbridge_cmd.cpp b/src/tunnelbridge_cmd.cpp
--- a/src/tunnelbridge_cmd.cpp
+++ b/src/tunnelbridge_cmd.cpp
@@ -1282,9 +1282,10 @@ static void TileLoop_TunnelBridge(TileIn
 	}
 }
 
-static void ClickTile_TunnelBridge(TileIndex tile)
+static bool ClickTile_TunnelBridge(TileIndex tile)
 {
 	/* not used */
+	return false;
 }