diff --git a/include/game_state.hpp b/include/game_state.hpp
index 9b3c6b6..92afe22 100644
--- a/include/game_state.hpp
+++ b/include/game_state.hpp
@@ -537,6 +537,12 @@ namespace Hanabi
   template<suit_t num_suits, player_t num_players, hand_index_t hand_size>
   void HanabiState<num_suits, num_players, hand_size>::init_backtracking_information()
   {
+    if (_weighted_draw_pile_size > 20)
+    {
+      std::stringstream ss;
+      ss << "Detected draw pile size of " << +_weighted_draw_pile_size << " is too big, can at most be 20.";
+      throw std::runtime_error(ss.str());
+    }
     ASSERT(not _relative_representation.initialized);
     // Note that this function does not have to be particularly performant, we only call it once to initialize.
     const Card trash = [this]() -> Card {