diff --git a/open_spiel/python/pybind11/bots.cc b/open_spiel/python/pybind11/bots.cc
index 18d20098ae..164b9f9dc7 100644
--- a/open_spiel/python/pybind11/bots.cc
+++ b/open_spiel/python/pybind11/bots.cc
@@ -34,7 +34,6 @@
 #include "pybind11/include/pybind11/detail/common.h"
 #include "pybind11/include/pybind11/pybind11.h"
 #include "pybind11/include/pybind11/pytypes.h"
-#include "pybind11/include/pybind11/smart_holder.h"
 
 // Optional headers.
 #if OPEN_SPIEL_BUILD_WITH_ROSHAMBO
diff --git a/open_spiel/python/pybind11/games_backgammon.cc b/open_spiel/python/pybind11/games_backgammon.cc
index 0917e12a4a..8945456d27 100644
--- a/open_spiel/python/pybind11/games_backgammon.cc
+++ b/open_spiel/python/pybind11/games_backgammon.cc
@@ -24,8 +24,6 @@ using open_spiel::State;
 using open_spiel::backgammon::BackgammonState;
 using open_spiel::backgammon::CheckerMove;
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(BackgammonState);
-
 void open_spiel::init_pyspiel_games_backgammon(py::module& m) {
   py::class_<CheckerMove>(m, "CheckerMove")
       .def_readwrite("pos", &CheckerMove::pos)
diff --git a/open_spiel/python/pybind11/games_bargaining.cc b/open_spiel/python/pybind11/games_bargaining.cc
index 0e1a1eaed1..2854b22e79 100644
--- a/open_spiel/python/pybind11/games_bargaining.cc
+++ b/open_spiel/python/pybind11/games_bargaining.cc
@@ -26,9 +26,6 @@ using open_spiel::bargaining::BargainingState;
 using open_spiel::bargaining::Instance;
 using open_spiel::bargaining::Offer;
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(BargainingGame);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(BargainingState);
-
 void open_spiel::init_pyspiel_games_bargaining(py::module& m) {
   py::class_<Instance>(m, "Instance")
       .def(py::init<>())
diff --git a/open_spiel/python/pybind11/games_bridge.cc b/open_spiel/python/pybind11/games_bridge.cc
index d0cbaecc56..16f4acfb66 100644
--- a/open_spiel/python/pybind11/games_bridge.cc
+++ b/open_spiel/python/pybind11/games_bridge.cc
@@ -20,9 +20,6 @@
 #include "open_spiel/python/pybind11/pybind11.h"
 #include "open_spiel/spiel.h"
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::bridge::BridgeGame);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::bridge::BridgeState);
-
 namespace open_spiel {
 
 namespace py = ::pybind11;
diff --git a/open_spiel/python/pybind11/games_chess.cc b/open_spiel/python/pybind11/games_chess.cc
index cfa888efe4..49d10eff40 100644
--- a/open_spiel/python/pybind11/games_chess.cc
+++ b/open_spiel/python/pybind11/games_chess.cc
@@ -24,7 +24,6 @@
 #include "open_spiel/spiel.h"
 #include "pybind11/include/pybind11/cast.h"
 #include "pybind11/include/pybind11/pybind11.h"
-#include "pybind11/include/pybind11/smart_holder.h"
 
 namespace py = ::pybind11;
 using open_spiel::Game;
@@ -38,10 +37,6 @@ using open_spiel::chess::Piece;
 using open_spiel::chess::PieceType;
 using open_spiel::chess::Move;
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(ChessGame);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(ChessState);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(ChessBoard);
-
 void open_spiel::init_pyspiel_games_chess(py::module& m) {
   py::module_ chess = m.def_submodule("chess");
 
diff --git a/open_spiel/python/pybind11/games_colored_trails.cc b/open_spiel/python/pybind11/games_colored_trails.cc
index 7dcf2e491e..3e8dc62836 100644
--- a/open_spiel/python/pybind11/games_colored_trails.cc
+++ b/open_spiel/python/pybind11/games_colored_trails.cc
@@ -32,9 +32,6 @@ using open_spiel::colored_trails::kDefaultNumColors;
 using open_spiel::colored_trails::kNumChipsLowerBound;
 using open_spiel::colored_trails::kNumChipsUpperBound;
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(ColoredTrailsGame);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(ColoredTrailsState);
-
 void open_spiel::init_pyspiel_games_colored_trails(py::module& m) {
   m.attr("NUM_COLORS") = py::int_(kDefaultNumColors);
   m.attr("NUM_CHIPS_LOWER_BOUND") = py::int_(kNumChipsLowerBound);
diff --git a/open_spiel/python/pybind11/games_dots_and_boxes.cc b/open_spiel/python/pybind11/games_dots_and_boxes.cc
index 2bf6745910..eca2273874 100644
--- a/open_spiel/python/pybind11/games_dots_and_boxes.cc
+++ b/open_spiel/python/pybind11/games_dots_and_boxes.cc
@@ -20,7 +20,6 @@
 
 #include "open_spiel/games/dots_and_boxes/dots_and_boxes.h"
 #include "open_spiel/spiel.h"
-#include "pybind11/include/pybind11/smart_holder.h"
 #include "pybind11/include/pybind11/pybind11.h"
 
 
@@ -29,8 +28,6 @@ using open_spiel::Game;
 using open_spiel::State;
 using open_spiel::dots_and_boxes::DotsAndBoxesState;
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(DotsAndBoxesState);
-
 void open_spiel::init_pyspiel_games_dots_and_boxes(py::module& m) {
   py::classh<DotsAndBoxesState, State>(m, "DotsAndBoxesState")
       .def("dbn_string", &DotsAndBoxesState::DbnString)
diff --git a/open_spiel/python/pybind11/games_euchre.cc b/open_spiel/python/pybind11/games_euchre.cc
index b98c071fa8..5edad146fe 100644
--- a/open_spiel/python/pybind11/games_euchre.cc
+++ b/open_spiel/python/pybind11/games_euchre.cc
@@ -25,9 +25,6 @@
 #include "pybind11/include/pybind11/detail/common.h"
 #include "pybind11_abseil/absl_casters.h"
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::euchre::EuchreGame);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::euchre::EuchreState);
-
 namespace open_spiel {
 
 namespace py = ::pybind11;
diff --git a/open_spiel/python/pybind11/games_gin_rummy.cc b/open_spiel/python/pybind11/games_gin_rummy.cc
index b631b3a983..b788a570c7 100644
--- a/open_spiel/python/pybind11/games_gin_rummy.cc
+++ b/open_spiel/python/pybind11/games_gin_rummy.cc
@@ -27,9 +27,6 @@
 #include "pybind11/include/pybind11/detail/common.h"
 #include "pybind11_abseil/absl_casters.h"
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::gin_rummy::GinRummyGame);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::gin_rummy::GinRummyState);
-
 namespace open_spiel {
 
 namespace py = ::pybind11;
diff --git a/open_spiel/python/pybind11/games_leduc_poker.cc b/open_spiel/python/pybind11/games_leduc_poker.cc
index 647f2506e3..8c1c1813c2 100644
--- a/open_spiel/python/pybind11/games_leduc_poker.cc
+++ b/open_spiel/python/pybind11/games_leduc_poker.cc
@@ -24,8 +24,6 @@ using open_spiel::State;
 using open_spiel::leduc_poker::LeducState;
 using open_spiel::leduc_poker::ActionType;
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(LeducState);
-
 void open_spiel::init_pyspiel_games_leduc_poker(py::module& m) {
   py::module_ leduc_poker = m.def_submodule("leduc_poker");
 
diff --git a/open_spiel/python/pybind11/games_negotiation.cc b/open_spiel/python/pybind11/games_negotiation.cc
index 7acd7e3e78..2064051aa0 100644
--- a/open_spiel/python/pybind11/games_negotiation.cc
+++ b/open_spiel/python/pybind11/games_negotiation.cc
@@ -23,8 +23,6 @@ using open_spiel::Game;
 using open_spiel::State;
 using open_spiel::negotiation::NegotiationState;
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(NegotiationState);
-
 void open_spiel::init_pyspiel_games_negotiation(py::module& m) {
   py::classh<NegotiationState, State>(m, "NegotiationState")
       .def("item_pool",
diff --git a/open_spiel/python/pybind11/games_spades.cc b/open_spiel/python/pybind11/games_spades.cc
index 8117c3877f..dcf00ae731 100644
--- a/open_spiel/python/pybind11/games_spades.cc
+++ b/open_spiel/python/pybind11/games_spades.cc
@@ -24,9 +24,6 @@
 #include "open_spiel/spiel.h"
 #include "open_spiel/spiel_utils.h"
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::spades::SpadesGame);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::spades::SpadesState);
-
 namespace open_spiel {
 
 namespace py = ::pybind11;
diff --git a/open_spiel/python/pybind11/games_tarok.cc b/open_spiel/python/pybind11/games_tarok.cc
index 3a469c3688..9cce775ee8 100644
--- a/open_spiel/python/pybind11/games_tarok.cc
+++ b/open_spiel/python/pybind11/games_tarok.cc
@@ -15,8 +15,6 @@
 #include "open_spiel/games/tarok/tarok.h"
 #include "open_spiel/python/pybind11/pybind11.h"
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::tarok::TarokState);
-
 namespace open_spiel {
 
 namespace py = ::pybind11;
diff --git a/open_spiel/python/pybind11/games_tiny_bridge.cc b/open_spiel/python/pybind11/games_tiny_bridge.cc
index eff5d6eaec..8d226712ac 100644
--- a/open_spiel/python/pybind11/games_tiny_bridge.cc
+++ b/open_spiel/python/pybind11/games_tiny_bridge.cc
@@ -24,9 +24,6 @@ using open_spiel::State;
 using open_spiel::tiny_bridge::TinyBridgeAuctionState;
 using open_spiel::tiny_bridge::TinyBridgePlayState;
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(TinyBridgePlayState);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(TinyBridgeAuctionState);
-
 void open_spiel::init_pyspiel_games_tiny_bridge(py::module& m) {
   py::classh<TinyBridgePlayState, State>(m, "TinyBridgePlayState")
       // Pickle support
diff --git a/open_spiel/python/pybind11/games_trade_comm.cc b/open_spiel/python/pybind11/games_trade_comm.cc
index 7f0d7a7924..0a09478107 100644
--- a/open_spiel/python/pybind11/games_trade_comm.cc
+++ b/open_spiel/python/pybind11/games_trade_comm.cc
@@ -23,7 +23,6 @@ using open_spiel::Game;
 using open_spiel::State;
 using open_spiel::trade_comm::TradeCommState;
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(TradeCommState);
 void open_spiel::init_pyspiel_games_trade_comm(py::module& m) {
   py::classh<TradeCommState, State>(m, "TradeCommState")
       // Pickle support
diff --git a/open_spiel/python/pybind11/pybind11.h b/open_spiel/python/pybind11/pybind11.h
index 206e328603..33ed721d7f 100644
--- a/open_spiel/python/pybind11/pybind11.h
+++ b/open_spiel/python/pybind11/pybind11.h
@@ -34,13 +34,8 @@
 #include "pybind11/include/pybind11/functional.h"  // IWYU pragma: keep
 #include "pybind11/include/pybind11/numpy.h"  // IWYU pragma: keep
 #include "pybind11/include/pybind11/pybind11.h"
-#include "pybind11/include/pybind11/smart_holder.h"  // IWYU pragma: keep
 #include "pybind11/include/pybind11/stl.h"  // IWYU pragma: keep
 
-// Runtime errors happen if we're inconsistent about whether or not a type has
-// PYBIND11_SMART_HOLDER_TYPE_CASTERS applied to it or not. So we do it mostly
-// in one place to help with consistency.
-
 namespace open_spiel {
 
 class Policy;
@@ -67,20 +62,6 @@ class ISMCTSBot;
 
 }  // namespace open_spiel
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::State);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::Game);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::Policy);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::TabularPolicy);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::PartialTabularPolicy);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::UniformPolicy);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::PreferredActionPolicy);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::NormalFormGame);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::matrix_game::MatrixGame);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::tensor_game::TensorGame);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::Bot);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::algorithms::MCTSBot);
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::algorithms::ISMCTSBot);
-
 namespace open_spiel {
 // Trampoline helper class to allow implementing Bots in Python. See
 // https://pybind11.readthedocs.io/en/stable/advanced/classes.html#overriding-virtual-functions-in-python