diff --git a/src/network/network.cpp b/src/network/network.cpp
index d237d9ac7a..fabc3bdb9f 100644
--- a/src/network/network.cpp
+++ b/src/network/network.cpp
@@ -703,7 +703,7 @@ void Network::AdvertiseHeartbeat()
 	json_object_set_new(body, "players", json_integer(network_get_num_players()));
 
 	json_t *gameInfo = json_object();
-	json_object_set_new(gameInfo, "mapSize", json_integer(gMapSizeMinus2));
+	json_object_set_new(gameInfo, "mapSize", json_integer(gMapSize - 2));
 	json_object_set_new(gameInfo, "day", json_integer(gDateMonthTicks));
 	json_object_set_new(gameInfo, "month", json_integer(gDateMonthsElapsed));
 	json_object_set_new(gameInfo, "guests", json_integer(gNumGuestsInPark));