diff --git a/src/water_cmd.cpp b/src/water_cmd.cpp
index 9d099f5dc3..6b4f41eb98 100644
--- a/src/water_cmd.cpp
+++ b/src/water_cmd.cpp
@@ -419,9 +419,11 @@ CommandCost CmdBuildCanal(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 		/* can't make water of water! */
 		if (IsTileType(tile, MP_WATER) && (!IsTileOwner(tile, OWNER_WATER) || wc == WATER_CLASS_SEA)) continue;
 
+		bool water = IsWaterTile(tile);
 		ret = DoCommand(tile, 0, 0, flags | DC_FORCE_CLEAR_TILE, CMD_LANDSCAPE_CLEAR);
 		if (ret.Failed()) return ret;
-		cost.AddCost(ret);
+
+		if (!water) cost.AddCost(ret);
 
 		if (flags & DC_EXEC) {
 			switch (wc) {