diff --git a/doc/fixes35.0 b/doc/fixes35.0
index 405cfe437..1396e8c21 100644
--- a/doc/fixes35.0
+++ b/doc/fixes35.0
@@ -181,6 +181,7 @@ same-race sacrifice can't damage high altars
 allow corpses on floor to be offered at high altars
 allow hero to attempt to offer the Amulet at ordinary altars
 shooting range for crossbow isn't affected by strength; multi-shot volley is
+right-handed boomerang throw travels counterclockwise
 
 
 Platform- and/or Interface-Specific Fixes
diff --git a/src/zap.c b/src/zap.c
index adce79186..c025c2891 100644
--- a/src/zap.c
+++ b/src/zap.c
@@ -3082,17 +3082,31 @@ struct obj *obj;
 int dx, dy;
 {
 	register int i, ct;
-	int boom = S_boomleft;	/* showsym[] index  */
+	int boom;	/* showsym[] index  */
 	struct monst *mtmp;
+	boolean counterclockwise = TRUE;	/* right-handed throw */
+
+/* counterclockwise traversal patterns:
+ *  ..........................54.................................
+ *  ..................43.....6..3....765.........................
+ *  ..........32.....5..2...7...2...8...4....87..................
+ *  .........4..1....6..1...8..1....9...3...9..6.....98..........
+ *  ..21@....5...@...7..@....9@......@12....@...5...@..7.....@9..
+ *  .3...9....6..9....89.....................1..4...1..6....1..8.
+ *  .4...8.....78.............................23....2..5...2...7.
+ *  ..567............................................34....3..6..
+ *  ........................................................45...
+ * (invert rows for corresponding clockwise patterns)
+ */
 
 	bhitpos.x = u.ux;
 	bhitpos.y = u.uy;
-
+	boom = counterclockwise ? S_boomleft : S_boomright;
 	for (i = 0; i < 8; i++) if (xdir[i] == dx && ydir[i] == dy) break;
 	tmp_at(DISP_FLASH, cmap_to_glyph(boom));
 	for (ct = 0; ct < 10; ct++) {
-		if(i == 8) i = 0;
-		boom = (boom == S_boomleft) ? S_boomright : S_boomleft;
+		i = (i + 8) % 8;	/* 0..7 (8 -> 0, -1 -> 7) */
+		boom = (S_boomleft + S_boomright - boom);	/* toggle */
 		tmp_at(DISP_CHANGE, cmap_to_glyph(boom));/* change glyph */
 		dx = xdir[i];
 		dy = ydir[i];
@@ -3126,11 +3140,13 @@ int dx, dy;
 		}
 		tmp_at(bhitpos.x, bhitpos.y);
 		delay_output();
-		if(ct % 5 != 0) i++;
 #ifdef SINKS
 		if(IS_SINK(levl[bhitpos.x][bhitpos.y].typ))
 			break;	/* boomerang falls on sink */
 #endif
+		/* ct==0, initial position, we want next delta to be same;
+		   ct==5, opposite position, repeat delta undoes first one */
+		if (ct % 5 != 0) i += (counterclockwise ? -1 : 1);
 	}
 	tmp_at(DISP_END, 0);	/* do not leave last symbol */
 	return (struct monst *)0;