diff --git a/xwords4/common/board.c b/xwords4/common/board.c
index 9ce4a2989..798e23954 100644
--- a/xwords4/common/board.c
+++ b/xwords4/common/board.c
@@ -1689,10 +1689,10 @@ board_toggle_showValues( BoardCtxt* board )
 } /* board_toggle_showValues */
 
 XP_Bool
-board_replaceTiles( BoardCtxt* board )
+board_replaceNTiles( BoardCtxt* board, XP_U16 nTiles )
 {
     XP_Bool result = XP_FALSE;
-    while ( replaceLastTile( board ) ) {
+    while ( 0 < nTiles-- && replaceLastTile( board ) ) {
         result = XP_TRUE;
     } 
 
@@ -1701,6 +1701,12 @@ board_replaceTiles( BoardCtxt* board )
     }
 
     return result;
+}
+
+XP_Bool
+board_replaceTiles( BoardCtxt* board )
+{
+    return board_replaceNTiles( board, MAX_TRAY_TILES );
 } /* board_replaceTiles */
 
 XP_Bool
diff --git a/xwords4/common/boardp.h b/xwords4/common/boardp.h
index 7124ef651..2f6133960 100644
--- a/xwords4/common/boardp.h
+++ b/xwords4/common/boardp.h
@@ -268,6 +268,7 @@ XP_Bool holdsPendingTile( BoardCtxt* board, XP_U16 pencol, XP_U16 penrow );
 
 XP_Bool moveTileToBoard( BoardCtxt* board, XP_U16 col, XP_U16 row, 
                          XP_U16 tileIndex, Tile blankFace );
+XP_Bool board_replaceNTiles( BoardCtxt* board, XP_U16 nTiles );
 
 void invalTilesUnderRect( BoardCtxt* board, const XP_Rect* rect );
 void invalCellRegion( BoardCtxt* board, XP_U16 colA, XP_U16 rowA, XP_U16 colB, 
diff --git a/xwords4/common/tray.c b/xwords4/common/tray.c
index 4e712edd7..bb2beb359 100644
--- a/xwords4/common/tray.c
+++ b/xwords4/common/tray.c
@@ -442,11 +442,16 @@ handleActionInTray( BoardCtxt* board, XP_S16 index, XP_Bool onDivider )
 #endif
     } else if ( index == -(MAX_TRAY_TILES) ) { /* pending score tile */
         result = board_commitTurn( board );
-#ifndef DISABLE_EMPTYTRAY_UNDO
+#if defined XWFEATURE_TRAYUNDO_ALL
     } else if ( index < 0 ) { /* other empty area */
         /* it better be true */
         (void)board_replaceTiles( board );
         result = XP_TRUE;
+#elif defined XWFEATURE_TRAYUNDO_ONE
+    } else if ( index < 0 ) { /* other empty area */
+        /* it better be true */
+        (void)board_replaceNTiles( board, 1 );
+        result = XP_TRUE;
 #endif
     }
     return result;