diff --git a/doc/fixes34.1 b/doc/fixes34.1
index 68b8c24d1..9c88e1f20 100644
--- a/doc/fixes34.1
+++ b/doc/fixes34.1
@@ -155,6 +155,7 @@ steed movement would use your speed if walking step by step
 kicking a known, unseen monster would sometimes leave behind an extra I symbol
 applying a lance against a long worm could cause an impossible
 a knight applying a lance did not do a caitiff check
+blessed gain level when already at level 30 won't reduce experience points
 
 
 Platform- and/or Interface-Specific Fixes
diff --git a/include/extern.h b/include/extern.h
index 335c4615e..1e290ae02 100644
--- a/include/extern.h
+++ b/include/extern.h
@@ -577,7 +577,7 @@ E void FDECL(more_experienced, (int,int));
 E void FDECL(losexp, (const char *));
 E void NDECL(newexplevel);
 E void FDECL(pluslvl, (BOOLEAN_P));
-E long NDECL(rndexp);
+E long FDECL(rndexp, (BOOLEAN_P));
 
 /* ### explode.c ### */
 
diff --git a/src/exper.c b/src/exper.c
index 37771a8bb..932b2833a 100644
--- a/src/exper.c
+++ b/src/exper.c
@@ -1,4 +1,4 @@
-/*	SCCS Id: @(#)exper.c	3.4	2002/06/23	*/
+/*	SCCS Id: @(#)exper.c	3.4	2002/07/11	*/
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -216,17 +216,32 @@ boolean incr;	/* true iff via incremental experience growth */
 	flags.botl = 1;
 }
 
+/* compute a random amount of experience points suitable for the hero's
+   experience level:  base number of points needed to reach the current
+   level plus a random portion of what it takes to get to the next level */
 long
-rndexp()
+rndexp(gaining)
+boolean gaining;	/* gaining XP via potion vs setting XP for polyself */
 {
-	long minexp, maxexp, diff, factor;
+	long minexp, maxexp, diff, factor, result;
 
 	minexp = (u.ulevel == 1) ? 0L : newuexp(u.ulevel - 1);
 	maxexp = newuexp(u.ulevel);
 	diff = maxexp - minexp,  factor = 1L;
+	/* make sure that `diff' is an argument which rn2() can handle */
 	while (diff >= (long)LARGEST_INT)
 	    diff /= 2L,  factor *= 2L;
-	return minexp + factor * (long)rn2((int)diff);
+	result = minexp + factor * (long)rn2((int)diff);
+	/* 3.4.1:  if already at level 30, add to current experience
+	   points rather than to threshold needed to reach the current
+	   level; otherwise blessed potions of gain level can result
+	   in lowering the experience points instead of raising them */
+	if (u.ulevel == MAXULEV && gaining) {
+	    result += (u.uexp - minexp);
+	    /* avoid wrapping (over 400 blessed potions needed for that...) */
+	    if (result < u.uexp) result = u.uexp;
+	}
+	return result;
 }
 
 /*exper.c*/
diff --git a/src/polyself.c b/src/polyself.c
index e080ba518..fb860ac75 100644
--- a/src/polyself.c
+++ b/src/polyself.c
@@ -1,4 +1,4 @@
-/*	SCCS Id: @(#)polyself.c	3.4	2002/06/23	*/
+/*	SCCS Id: @(#)polyself.c	3.4	2002/07/11	*/
 /*	Copyright (C) 1987, 1988, 1989 by Ken Arromdee */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -159,7 +159,7 @@ newman()
 	reset_rndmonst(NON_PM);	/* new monster generation criteria */
 
 	/* random experience points for the new experience level */
-	u.uexp = rndexp();
+	u.uexp = rndexp(FALSE);
 
 	/* u.uhpmax * u.ulevel / oldlvl: proportionate hit points to new level
 	 * -10 and +10: don't apply proportionate HP to 10 of a starting
diff --git a/src/potion.c b/src/potion.c
index bbade3880..fe8726a09 100644
--- a/src/potion.c
+++ b/src/potion.c
@@ -1,4 +1,4 @@
-/*	SCCS Id: @(#)potion.c	3.4	2002/03/23	*/
+/*	SCCS Id: @(#)potion.c	3.4	2002/07/11	*/
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -770,7 +770,7 @@ peffects(otmp)
 			/* blessed potions place you at a random spot in the
 			 * middle of the new level instead of the low point
 			 */
-			u.uexp = rndexp();
+			u.uexp = rndexp(TRUE);
 		break;
 	case POT_HEALING:
 		You_feel("better.");