--- nethack-3.4.3/src/do.c	2003-12-07 16:39:13.000000000 -0700
+++ patchhack/src/do.c	2014-11-16 14:15:26.061925745 -0700
@@ -246,7 +246,8 @@
 	} else {
 		pline("%s %s on the altar.", Doname2(obj),
 			otense(obj, "land"));
-		obj->bknown = 1;
+                if (obj->oclass != COIN_CLASS)
+			obj->bknown = 1;
 	}
 }