diff --git a/src/ai/api/ai_tile.cpp b/src/ai/api/ai_tile.cpp
index ea13fe456c..f54285477c 100644
--- a/src/ai/api/ai_tile.cpp
+++ b/src/ai/api/ai_tile.cpp
@@ -177,7 +177,7 @@
 
 /* static */ int32 AITile::GetCargoAcceptance(TileIndex tile, CargoID cargo_type, int width, int height, int radius)
 {
-	if (!::IsValidTile(tile) || width <= 0 || height <= 0 || radius <= 0) return -1;
+	if (!::IsValidTile(tile) || width <= 0 || height <= 0 || radius < 0) return -1;
 
 	CargoArray acceptance = ::GetAcceptanceAroundTiles(tile, width, height, _settings_game.station.modified_catchment ? radius : (int)CA_UNMODIFIED);
 	return acceptance[cargo_type];
@@ -185,7 +185,7 @@
 
 /* static */ int32 AITile::GetCargoProduction(TileIndex tile, CargoID cargo_type, int width, int height, int radius)
 {
-	if (!::IsValidTile(tile) || width <= 0 || height <= 0 || radius <= 0) return -1;
+	if (!::IsValidTile(tile) || width <= 0 || height <= 0 || radius < 0) return -1;
 
 	CargoArray produced = ::GetProductionAroundTiles(tile, width, height, _settings_game.station.modified_catchment ? radius : (int)CA_UNMODIFIED);
 	return produced[cargo_type];
diff --git a/src/ai/api/ai_tile.hpp b/src/ai/api/ai_tile.hpp
index 965a829f63..78abfde73a 100644
--- a/src/ai/api/ai_tile.hpp
+++ b/src/ai/api/ai_tile.hpp
@@ -305,7 +305,7 @@ public:
 	 * @pre AIMap::IsValidTile(tile).
 	 * @pre width > 0.
 	 * @pre height > 0.
-	 * @pre radius > 0.
+	 * @pre radius >= 0.
 	 * @return Value below 8 means no acceptance; the more the better.
 	 */
 	static int32 GetCargoAcceptance(TileIndex tile, CargoID cargo_type, int width, int height, int radius);
@@ -322,7 +322,7 @@ public:
 	 * @pre AIMap::IsValidTile(tile).
 	 * @pre width > 0.
 	 * @pre height > 0.
-	 * @pre radius > 0.
+	 * @pre radius >= 0.
 	 * @return The tiles that produce this cargo within radius of the tile.
 	 * @note Town(houses) are not included in the value.
 	 */