--- a/industry_gui.c	Sat Jan 21 20:34:17 2006 +0000
+++ b/industry_gui.c	Sat Jan 21 21:45:34 2006 +0000
@@ -267,6 +267,7 @@
 
 void ShowBuildIndustryWindow(void)
 {
+	if (_current_player == OWNER_SPECTATOR) return;
 	AllocateWindowDescFront(_industry_window_desc[_patches.build_rawmaterial_ind][_opt_ptr->landscape],0);
 }