--- a/ai/ai.c	Tue Dec 06 23:37:44 2005 +0000
+++ b/ai/ai.c	Wed Dec 07 14:56:42 2005 +0000
@@ -137,7 +137,7 @@
 
 	res = AI_DoCommand(tile, p1, p2, flags & ~DC_EXEC, procc);
 	if (CmdFailed(res))
-		return -1;
+		return CMD_ERROR;
 
 	/* Save the command and his things, together with the unique_id */
 	new = malloc(sizeof(AICommand));