--- a/tree_cmd.c	Sun Sep 09 16:59:56 2007 +0000
+++ b/tree_cmd.c	Sun Sep 09 20:36:15 2007 +0000
@@ -249,6 +249,11 @@
 					cost += _price.build_trees * 2;
 					break;
 
+				case MP_WATER:
+					msg = STR_3807_CAN_T_BUILD_ON_WATER;
+					continue;
+					break;
+
 				case MP_CLEAR:
 					if (!IsTileOwner(tile, OWNER_NONE)) {
 						msg = STR_2804_SITE_UNSUITABLE;