diff --git a/World-map-generation.md b/World-map-generation.md
index f117473..5c61291 100644
--- a/World-map-generation.md
+++ b/World-map-generation.md
@@ -3,6 +3,7 @@ The Release package includes a map, however you can create your own following si
 * `world_map.jpg` should be square (i.e. 32768 x 32768 px)
 * The projection of the map is Mercator based on the World Geodetic System (WGS) 1984 geographic coordinate system (datum)
 * Longitude and latitude cover the map from -180 to 180 and -85 to 85, respectively. Note that latitude does not go up to 90 (since most available maps do not include the 5 initial degrees)
+* Center of the map should be 0-degrees latitude and 0-degrees longitude (where the prime meridian and equator intersect)
 
 With those conditions fulfilled, place the input map in: `sdcard/ADSB/world_map.jpg` and then run `firmware/tools/generate_world_map.bin.py`. Your map will be generated on: `sdcard/ADSB/world_map.bin`