--- a/src/train_gui.cpp	Sat May 24 23:18:21 2008 +0000
+++ b/src/train_gui.cpp	Sun May 25 09:40:44 2008 +0000
@@ -28,8 +28,8 @@
 	if (!success) return;
 
 	/* find a locomotive in the depot. */
-	Vehicle *found = NULL;
-	Vehicle *v;
+	const Vehicle *found = NULL;
+	const Vehicle *v;
 	FOR_ALL_VEHICLES(v) {
 		if (v->type == VEH_TRAIN && IsFrontEngine(v) &&
 				v->tile == tile &&