diff --git a/src/CommandFormats.hh b/src/CommandFormats.hh
index a3012c8e..b2e76bf8 100644
--- a/src/CommandFormats.hh
+++ b/src/CommandFormats.hh
@@ -2784,8 +2784,7 @@ struct S_Unknown_BB_F0 {
 struct G_ItemSubcommand {
   uint8_t command;
   uint8_t size;
-  uint8_t client_id;
-  uint8_t unused;
+  le_uint16_t client_id;
   le_uint32_t item_id;
   le_uint32_t amount;
 };
@@ -2939,8 +2938,7 @@ struct G_SetPlayerVisibility_6x22_6x23 {
 struct G_EquipItem_6x25 {
   uint8_t command;
   uint8_t size;
-  uint8_t client_id;
-  uint8_t unused;
+  le_uint16_t client_id;
   le_uint32_t item_id;
   le_uint32_t equip_slot;
 };
@@ -2950,8 +2948,7 @@ struct G_EquipItem_6x25 {
 struct G_UnequipItem_6x26 {
   uint8_t command;
   uint8_t size;
-  uint8_t client_id;
-  uint8_t unused;
+  le_uint16_t client_id;
   le_uint32_t item_id;
   le_uint32_t unused2;
 };
@@ -2961,8 +2958,7 @@ struct G_UnequipItem_6x26 {
 struct G_UseItem_6x27 {
   uint8_t command;
   uint8_t size;
-  uint8_t client_id;
-  uint8_t unused;
+  le_uint16_t client_id;
   le_uint32_t item_id;
 };
 
@@ -2986,8 +2982,7 @@ struct G_FeedMAG_6x28 {
 struct G_PlayerDropItem_6x2A {
   uint8_t command;
   uint8_t size;
-  uint8_t client_id;
-  uint8_t unused;
+  le_uint16_t client_id;
   le_uint16_t unused2; // should be 1
   le_uint16_t area;
   le_uint32_t item_id;
@@ -3001,8 +2996,7 @@ struct G_PlayerDropItem_6x2A {
 struct G_PlayerCreateInventoryItem_DC_6x2B {
   uint8_t command;
   uint8_t size;
-  uint8_t client_id;
-  uint8_t unused;
+  le_uint16_t client_id;
   ItemData item;
 };
 
@@ -3020,8 +3014,7 @@ struct G_PlayerCreateInventoryItem_PC_V3_BB_6x2B : G_PlayerCreateInventoryItem_D
 struct G_LevelUp_6x30 {
   uint8_t command;
   uint8_t size;
-  uint8_t client_id;
-  uint8_t unused;
+  le_uint16_t client_id;
   le_uint16_t atp;
   le_uint16_t mst;
   le_uint16_t evp;
@@ -3132,8 +3125,7 @@ struct G_PickUpItem_6x59 {
 struct G_PickUpItemRequest_6x5A {
   uint8_t command;
   uint8_t size;
-  uint8_t client_id;
-  uint8_t unused;
+  le_uint16_t client_id;
   le_uint32_t item_id;
   uint8_t area;
   uint8_t unused2[3];
@@ -3147,8 +3139,7 @@ struct G_PickUpItemRequest_6x5A {
 struct G_DropStackedItem_DC_6x5D {
   uint8_t subcommand;
   uint8_t size;
-  uint8_t client_id;
-  uint8_t unused;
+  le_uint16_t client_id;
   le_uint16_t area;
   le_uint16_t unused2;
   le_float x;
@@ -3165,8 +3156,7 @@ struct G_DropStackedItem_PC_V3_BB_6x5D : G_DropStackedItem_DC_6x5D {
 struct G_BuyShopItem_6x5E {
   uint8_t subcommand;
   uint8_t size;
-  uint8_t client_id;
-  uint8_t unused;
+  le_uint16_t client_id;
   ItemData item;
 };
 
@@ -3346,8 +3336,7 @@ struct G_BuyShopItem_BB_6xB7 {
 struct G_IdentifyResult_BB_6xB9 {
   uint8_t subcommand;
   uint8_t size;
-  uint8_t client_id;
-  uint8_t unused;
+  le_uint16_t client_id;
   ItemData item;
 };
 
@@ -3403,8 +3392,7 @@ struct G_CreateInventoryItem_BB_6xBE {
 struct G_GiveExperience_BB_6xBF {
   uint8_t subcommand;
   uint8_t size;
-  uint8_t client_id;
-  uint8_t unused;
+  le_uint16_t client_id;
   le_uint32_t amount;
 };
 
@@ -3421,8 +3409,7 @@ struct G_GiveExperience_BB_6xBF {
 struct G_SplitStackedItem_6xC3 {
   uint8_t command;
   uint8_t size;
-  uint8_t client_id;
-  uint8_t unused;
+  le_uint16_t client_id;
   le_uint16_t area;
   le_uint16_t unused2;
   le_float x;
diff --git a/src/ReceiveSubcommands.cc b/src/ReceiveSubcommands.cc
index f5b3c2ab..ebd4517b 100644
--- a/src/ReceiveSubcommands.cc
+++ b/src/ReceiveSubcommands.cc
@@ -293,8 +293,8 @@ static void on_subcommand_player_drop_item(shared_ptr<ServerState>,
     l->add_item(c->game_data.player()->remove_item(cmd->item_id, 0),
         cmd->area, cmd->x, cmd->z);
 
-    l->log.info("Player %hhu dropped item %08" PRIX32 " at %hu:(%g, %g)",
-        cmd->client_id, cmd->item_id.load(), cmd->area.load(), cmd->x.load(), cmd->z.load());
+    l->log.info("Player %hu dropped item %08" PRIX32 " at %hu:(%g, %g)",
+        cmd->client_id.load(), cmd->item_id.load(), cmd->area.load(), cmd->x.load(), cmd->z.load());
     c->game_data.player()->print_inventory(stderr);
   }
 
@@ -323,8 +323,8 @@ static void on_subcommand_create_inventory_item(shared_ptr<ServerState>,
     item.data = cmd->item;
     c->game_data.player()->add_item(item);
 
-    l->log.info("Player %hhu created inventory item %08" PRIX32,
-        cmd->client_id, cmd->item.id.load());
+    l->log.info("Player %hu created inventory item %08" PRIX32,
+        cmd->client_id.load(), cmd->item.id.load());
     c->game_data.player()->print_inventory(stderr);
   }
 
@@ -354,8 +354,8 @@ static void on_subcommand_drop_partial_stack(shared_ptr<ServerState>,
     item.data = cmd->data;
     l->add_item(item, cmd->area, cmd->x, cmd->z);
 
-    l->log.info("Player %hhu split stack to create ground item %08" PRIX32 " at %hu:(%g, %g)",
-        cmd->client_id, item.data.id.load(), cmd->area.load(), cmd->x.load(), cmd->z.load());
+    l->log.info("Player %hu split stack to create ground item %08" PRIX32 " at %hu:(%g, %g)",
+        cmd->client_id.load(), item.data.id.load(), cmd->area.load(), cmd->x.load(), cmd->z.load());
     c->game_data.player()->print_inventory(stderr);
   }
 
@@ -391,8 +391,8 @@ static void on_subcommand_drop_partial_stack_bb(shared_ptr<ServerState>,
 
     l->add_item(item, cmd->area, cmd->x, cmd->z);
 
-    l->log.info("Player %hhu split stack %08" PRIX32 " (%" PRIu32 " of them) at %hu:(%g, %g)",
-        cmd->client_id, cmd->item_id.load(), cmd->amount.load(),
+    l->log.info("Player %hu split stack %08" PRIX32 " (%" PRIu32 " of them) at %hu:(%g, %g)",
+        cmd->client_id.load(), cmd->item_id.load(), cmd->amount.load(),
         cmd->area.load(), cmd->x.load(), cmd->z.load());
     c->game_data.player()->print_inventory(stderr);
 
@@ -422,8 +422,8 @@ static void on_subcommand_buy_shop_item(shared_ptr<ServerState>,
     item.data = cmd->item;
     c->game_data.player()->add_item(item);
 
-    l->log.info("Player %hhu bought item %08" PRIX32 " from shop",
-        cmd->client_id, item.data.id.load());
+    l->log.info("Player %hu bought item %08" PRIX32 " from shop",
+        cmd->client_id.load(), item.data.id.load());
     c->game_data.player()->print_inventory(stderr);
   }
 
@@ -501,7 +501,8 @@ static void on_subcommand_pick_up_item_request(shared_ptr<ServerState>,
 
     c->game_data.player()->add_item(l->remove_item(cmd->item_id));
 
-    l->log.info("Player %hhu picked up %08" PRIX32, cmd->client_id, cmd->item_id.load());
+    l->log.info("Player %hu picked up %08" PRIX32,
+        cmd->client_id.load(), cmd->item_id.load());
     c->game_data.player()->print_inventory(stderr);
 
     send_pick_up_item(l, c, cmd->item_id, cmd->area);
@@ -549,7 +550,8 @@ static void on_subcommand_use_item(shared_ptr<ServerState>,
     size_t index = c->game_data.player()->inventory.find_item(cmd->item_id);
     player_use_item(c, index);
 
-    l->log.info("Player used item %hhu:%08" PRIX32, cmd->client_id, cmd->item_id.load());
+    l->log.info("Player used item %hu:%08" PRIX32,
+        cmd->client_id.load(), cmd->item_id.load());
     c->game_data.player()->print_inventory(stderr);
   }
 
@@ -940,8 +942,8 @@ static void on_subcommand_destroy_inventory_item(shared_ptr<ServerState>,
   }
   if (l->flags & Lobby::Flag::ITEM_TRACKING_ENABLED) {
     c->game_data.player()->remove_item(cmd->item_id, cmd->amount);
-    l->log.info("Inventory item %hhu:%08" PRIX32 " destroyed (%" PRIX32 " of them)",
-        cmd->client_id, cmd->item_id.load(), cmd->amount.load());
+    l->log.info("Inventory item %hu:%08" PRIX32 " destroyed (%" PRIX32 " of them)",
+        cmd->client_id.load(), cmd->item_id.load(), cmd->amount.load());
     c->game_data.player()->print_inventory(stderr);
     forward_subcommand(l, c, command, flag, data);
   }
@@ -988,7 +990,6 @@ static void on_subcommand_identify_item_bb(shared_ptr<ServerState>,
     res.subcommand = 0xB9;
     res.size = sizeof(res) / 4;
     res.client_id = c->lobby_client_id;
-    res.unused = 0;
     res.item = c->game_data.identify_result.data;
     send_command_t(l, 0x60, 0x00, res);
 
diff --git a/src/SendCommands.cc b/src/SendCommands.cc
index 06ed7d2c..95d32236 100644
--- a/src/SendCommands.cc
+++ b/src/SendCommands.cc
@@ -1458,7 +1458,7 @@ void send_drop_stacked_item(shared_ptr<Lobby> l, const ItemData& item,
   // TODO: Is this order correct? The original code sent {item, 0}, but it seems
   // GC sends {0, item} (the last two fields in the struct are switched).
   G_DropStackedItem_PC_V3_BB_6x5D cmd = {
-      {0x5D, 0x0A, 0x00, 0x00, area, 0, x, z, item}, 0};
+      {0x5D, 0x0A, 0x0000, area, 0, x, z, item}, 0};
   send_command_t(l, 0x60, 0x00, cmd);
 }
 
@@ -1482,7 +1482,7 @@ void send_create_inventory_item(shared_ptr<Lobby> l, shared_ptr<Client> c,
 void send_destroy_item(shared_ptr<Lobby> l, shared_ptr<Client> c,
     uint32_t item_id, uint32_t amount) {
   G_ItemSubcommand cmd = {
-      0x29, 0x03, c->lobby_client_id, 0x00, item_id, amount};
+      0x29, 0x03, c->lobby_client_id, item_id, amount};
   send_command_t(l, 0x60, 0x00, cmd);
 }
 
@@ -1543,7 +1543,6 @@ void send_level_up(shared_ptr<Lobby> l, shared_ptr<Client> c) {
       0x30,
       sizeof(G_LevelUp_6x30) / 4,
       c->lobby_client_id,
-      0,
       stats.atp,
       stats.mst,
       stats.evp,
@@ -1558,7 +1557,7 @@ void send_level_up(shared_ptr<Lobby> l, shared_ptr<Client> c) {
 void send_give_experience(shared_ptr<Lobby> l, shared_ptr<Client> c,
     uint32_t amount) {
   G_GiveExperience_BB_6xBF cmd = {
-      0xBF, sizeof(G_GiveExperience_BB_6xBF) / 4, c->lobby_client_id, 0, amount};
+      0xBF, sizeof(G_GiveExperience_BB_6xBF) / 4, c->lobby_client_id, amount};
   send_command_t(l, 0x60, 0x00, cmd);
 }