diff --git a/homeworld_logic.lua b/homeworld_logic.lua
index de0cf01..891dd64 100644
--- a/homeworld_logic.lua
+++ b/homeworld_logic.lua
@@ -318,7 +318,7 @@ function Homeworld:tick( tick )
    for player_index = 1, #game.players do
       local player = game.players[player_index]
       local held_item = player.cursor_stack
-      local holding_pda = (held_item.valid_for_read and held_item.name == pda_name)
+      local holding_pda = (held_item and held_item.valid_for_read and held_item.name == pda_name)
       if self.state.using_pda[player_index] and not holding_pda then
          self.state.using_pda[player_index] = nil
          self:hide_gui(player_index)