diff --git a/xwords4/common/model.c b/xwords4/common/model.c
index 8aeb265eb..2bcb06c38 100644
--- a/xwords4/common/model.c
+++ b/xwords4/common/model.c
@@ -1,6 +1,6 @@
 /* -*- compile-command: "cd ../linux && make -j3 MEMDEBUG=TRUE"; -*- */
 /* 
- * Copyright 2000 - 2017 by Eric House (xwords@eehouse.org).  All rights
+ * Copyright 2000 - 2022 by Eric House (xwords@eehouse.org).  All rights
  * reserved.
  *
  * This program is free software; you can redistribute it and/or
@@ -1124,17 +1124,16 @@ model_undoLatestMoves( ModelCtxt* model, XWEnv xwe, PoolContext* pool,
 } /* model_undoLatestMoves */
 
 void
-model_trayToStream( ModelCtxt* model, XP_S16 turn, XWStreamCtxt* stream )
+model_trayToStream( const ModelCtxt* model, XP_S16 turn, XWStreamCtxt* stream )
 {
-    PlayerCtxt* player;
     XP_ASSERT( turn >= 0 );
-    player = &model->players[turn];
+    const PlayerCtxt* player = &model->players[turn];
 
     traySetToStream( stream, &player->trayTiles );
 } /* model_trayToStream */
 
 void
-model_currentMoveToMoveInfo( ModelCtxt* model, XP_S16 turn,
+model_currentMoveToMoveInfo( const ModelCtxt* model, XP_S16 turn,
                              MoveInfo* moveInfo )
 {
     XP_ASSERT( turn >= 0 );
@@ -1178,7 +1177,7 @@ model_currentMoveToMoveInfo( ModelCtxt* model, XP_S16 turn,
 }
 
 void
-model_currentMoveToStream( ModelCtxt* model, XP_S16 turn, 
+model_currentMoveToStream( const ModelCtxt* model, XP_S16 turn,
                            XWStreamCtxt* stream )
 {
 #ifdef STREAM_VERS_BIGBOARD
@@ -1431,22 +1430,20 @@ model_getCurrentMoveIsVertical( const ModelCtxt* model, XP_S16 turn,
 }
 
 void
-model_getCurrentMoveTile( ModelCtxt* model, XP_S16 turn, XP_S16* index,
+model_getCurrentMoveTile( const ModelCtxt* model, XP_S16 turn, XP_S16* index,
                           Tile* tile, XP_U16* col, XP_U16* row, 
                           XP_Bool* isBlank )
 {
-    PlayerCtxt* player;
-    PendingTile* pt;
     XP_ASSERT( turn >= 0 );
 
-    player = &model->players[turn];
+    const PlayerCtxt* player = &model->players[turn];
     XP_ASSERT( *index < player->nPending );
     
     if ( *index < 0 ) {
         *index = player->nPending - 1;
     }
 
-    pt = &player->pendingTiles[*index];
+    const PendingTile* pt = &player->pendingTiles[*index];
 
     *col = pt->col;
     *row = pt->row;
diff --git a/xwords4/common/model.h b/xwords4/common/model.h
index bc40ef157..1058d56f4 100644
--- a/xwords4/common/model.h
+++ b/xwords4/common/model.h
@@ -166,7 +166,7 @@ XP_U16 model_getCurrentMoveCount( const ModelCtxt* model, XP_S16 turn );
 XP_Bool model_getCurrentMoveIsVertical( const ModelCtxt* model, XP_S16 turn,
                                         XP_Bool* isHorizontal );
 
-void model_getCurrentMoveTile( ModelCtxt* model, XP_S16 turn, XP_S16* index,
+void model_getCurrentMoveTile( const ModelCtxt* model, XP_S16 turn, XP_S16* index,
                                Tile* tile, XP_U16* col, XP_U16* row, 
                                XP_Bool* isBlank );
 
@@ -193,11 +193,11 @@ XP_Bool model_undoLatestMoves( ModelCtxt* model, XWEnv xwe, PoolContext* pool,
 void model_rejectPreviousMove( ModelCtxt* model, XWEnv xwe,
                                PoolContext* pool, XP_U16* turn );
 
-void model_trayToStream( ModelCtxt* model, XP_S16 turn, 
+void model_trayToStream( const ModelCtxt* model, XP_S16 turn,
                          XWStreamCtxt* stream );
-void model_currentMoveToStream( ModelCtxt* model, XP_S16 turn, 
+void model_currentMoveToStream( const ModelCtxt* model, XP_S16 turn,
                                 XWStreamCtxt* stream );
-void model_currentMoveToMoveInfo( ModelCtxt* model, XP_S16 turn,
+void model_currentMoveToMoveInfo( const ModelCtxt* model, XP_S16 turn,
                                   MoveInfo* moveInfo );
 XP_Bool model_makeTurnFromStream( ModelCtxt* model, XWEnv xwe, XP_U16 playerNum,
                                   XWStreamCtxt* stream );