diff --git a/src/ai/api/ai_tile.cpp b/src/ai/api/ai_tile.cpp
--- a/src/ai/api/ai_tile.cpp
+++ b/src/ai/api/ai_tile.cpp
@@ -156,14 +156,14 @@
 {
 	if (!::IsValidTile(tile)) return -1;
 
-	return ::GetTilePixelZ(tile) / ::TILE_HEIGHT;
+	return ::GetTileZ(tile);
 }
 
 /* static */ int32 AITile::GetMaxHeight(TileIndex tile)
 {
 	if (!::IsValidTile(tile)) return -1;
 
-	return ::GetTileMaxPixelZ(tile) / ::TILE_HEIGHT;
+	return ::GetTileMaxZ(tile);
 }
 
 /* static */ int32 AITile::GetCornerHeight(TileIndex tile, Corner corner)
@@ -171,8 +171,8 @@
 	if (!::IsValidTile(tile) || !::IsValidCorner((::Corner)corner)) return -1;
 
 	uint z;
-	::Slope slope = ::GetTilePixelSlope(tile, &z);
-	return (z + ::GetSlopePixelZInCorner(slope, (::Corner)corner)) / ::TILE_HEIGHT;
+	::Slope slope = ::GetTileSlope(tile, &z);
+	return (z + ::GetSlopeZInCorner(slope, (::Corner)corner));
 }
 
 /* static */ AICompany::CompanyID AITile::GetOwner(TileIndex tile)
diff --git a/src/ai/api/ai_tunnel.cpp b/src/ai/api/ai_tunnel.cpp
--- a/src/ai/api/ai_tunnel.cpp
+++ b/src/ai/api/ai_tunnel.cpp
@@ -30,7 +30,7 @@
 	if (IsTunnelTile(tile)) return ::GetOtherTunnelEnd(tile);
 
 	uint start_z;
-	Slope start_tileh = ::GetTilePixelSlope(tile, &start_z);
+	Slope start_tileh = ::GetTileSlope(tile, &start_z);
 	DiagDirection direction = ::GetInclinedSlopeDirection(start_tileh);
 	if (direction == INVALID_DIAGDIR) return INVALID_TILE;
 
@@ -40,7 +40,7 @@
 		tile += delta;
 		if (!::IsValidTile(tile)) return INVALID_TILE;
 
-		::GetTilePixelSlope(tile, &end_z);
+		::GetTileSlope(tile, &end_z);
 	} while (start_z != end_z);
 
 	return tile;