diff --git a/third_party/marl/BUILD.gn b/third_party/marl/BUILD.gn
index d7cb142..4c02648 100644
--- a/third_party/marl/BUILD.gn
+++ b/third_party/marl/BUILD.gn
@@ -18,6 +18,9 @@
 
 config("marl_config") {
   include_dirs = [ "include" ]
+  if (!is_win) {
+    defines = [ "MARL_USE_PTHREAD_THREAD_LOCAL=1" ]
+  }
 }
 
 swiftshader_source_set("Marl_headers") {
diff --git a/third_party/marl/CMakeLists.txt b/third_party/marl/CMakeLists.txt
index c84076d..5f17ee8 100644
--- a/third_party/marl/CMakeLists.txt
+++ b/third_party/marl/CMakeLists.txt
@@ -46,6 +46,7 @@
 option_if_not_defined(MARL_BUILD_TESTS "Build tests" OFF)
 option_if_not_defined(MARL_BUILD_BENCHMARKS "Build benchmarks" OFF)
 option_if_not_defined(MARL_BUILD_SHARED "Build marl as a shared / dynamic library (default static)" OFF)
+option_if_not_defined(MARL_USE_PTHREAD_THREAD_LOCAL "Use pthreads for thread local storage" OFF)
 option_if_not_defined(MARL_ASAN "Build marl with address sanitizer" OFF)
 option_if_not_defined(MARL_MSAN "Build marl with memory sanitizer" OFF)
 option_if_not_defined(MARL_TSAN "Build marl with thread sanitizer" OFF)
@@ -224,6 +225,11 @@
         endif()
     endif(MARL_WARNINGS_AS_ERRORS)
 
+    if(MARL_USE_PTHREAD_THREAD_LOCAL)
+        target_compile_definitions(${target} PRIVATE "MARL_USE_PTHREAD_THREAD_LOCAL=1")
+        target_link_libraries(${target} PUBLIC pthread)
+    endif()
+
     if(MARL_ASAN)
         target_compile_options(${target} PUBLIC "-fsanitize=address")
         target_link_libraries(${target} PUBLIC "-fsanitize=address")
diff --git a/third_party/marl/include/marl/sanitizers.h b/third_party/marl/include/marl/sanitizers.h
index 6993066..3f26d4a 100644
--- a/third_party/marl/include/marl/sanitizers.h
+++ b/third_party/marl/include/marl/sanitizers.h
@@ -78,14 +78,4 @@
 #define THREAD_SANITIZER_ONLY(x)
 #endif  // THREAD_SANITIZER_ENABLED
 
-// The MSAN_UNPOISON macro marks uninitialized memory as initialized for MSAN.
-// It can be used to suppress false-positive MSAN errors before reading
-// thread-local variables. See https://github.com/google/sanitizers/issues/1265
-#if MEMORY_SANITIZER_ENABLED
-#include <sanitizer/msan_interface.h>
-#define MSAN_UNPOISON(p, size) __msan_unpoison(p, size)
-#else
-#define MSAN_UNPOISON(p, size)
-#endif
-
 #endif  // marl_sanitizers_h
diff --git a/third_party/marl/include/marl/scheduler.h b/third_party/marl/include/marl/scheduler.h
index 48acf02..b3159b8 100644
--- a/third_party/marl/include/marl/scheduler.h
+++ b/third_party/marl/include/marl/scheduler.h
@@ -24,6 +24,7 @@
 #include "sanitizers.h"
 #include "task.h"
 #include "thread.h"
+#include "thread_local.h"
 
 #include <array>
 #include <atomic>
@@ -464,7 +465,7 @@
     };
 
     // The current worker bound to the current thread.
-    static thread_local Worker* current;
+    MARL_DECLARE_THREAD_LOCAL(Worker*, current);
 
     Mode const mode;
     Scheduler* const scheduler;
@@ -492,7 +493,7 @@
   static void setBound(Scheduler* scheduler);
 
   // The scheduler currently bound to the current thread.
-  static thread_local Scheduler* bound;
+  MARL_DECLARE_THREAD_LOCAL(Scheduler*, bound);
 
   // The immutable configuration used to build the scheduler.
   const Config cfg;
@@ -574,7 +575,6 @@
 }
 
 Scheduler::Worker* Scheduler::Worker::getCurrent() {
-  MSAN_UNPOISON(&current, sizeof(Worker*));
   return Worker::current;
 }
 
diff --git a/third_party/marl/include/marl/thread_local.h b/third_party/marl/include/marl/thread_local.h
new file mode 100644
index 0000000..1165866
--- /dev/null
+++ b/third_party/marl/include/marl/thread_local.h
@@ -0,0 +1,60 @@
+// Copyright 2023 The Marl Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// A wrapper around a thread_local variable, or a pthread key
+
+#ifndef marl_thread_local_h
+#define marl_thread_local_h
+
+#ifdef MARL_USE_PTHREAD_THREAD_LOCAL
+#include "debug.h"
+
+#include <pthread.h>
+#include <type_traits>
+
+template <typename T>
+class ThreadLocal {
+  static_assert(std::is_pointer<T>::value,
+                "The current implementation of ThreadLocal requires that T "
+                "must be a pointer");
+
+ public:
+  inline ThreadLocal(T v) {
+    pthread_key_create(&key, NULL);
+    pthread_setspecific(key, v);
+  };
+  inline ~ThreadLocal() { pthread_key_delete(key); }
+  inline operator T() const { return static_cast<T>(pthread_getspecific(key)); }
+  inline ThreadLocal& operator=(T v) {
+    pthread_setspecific(key, v);
+    return *this;
+  }
+
+ private:
+  pthread_key_t key;
+};
+
+#define MARL_DECLARE_THREAD_LOCAL(TYPE, NAME) static ThreadLocal<TYPE> NAME;
+#define MARL_INSTANTIATE_THREAD_LOCAL(TYPE, NAME, VALUE) \
+  ThreadLocal<TYPE> NAME = VALUE;
+
+#else
+
+#define MARL_DECLARE_THREAD_LOCAL(TYPE, NAME) static thread_local TYPE NAME;
+#define MARL_INSTANTIATE_THREAD_LOCAL(TYPE, NAME, VALUE) \
+  thread_local TYPE NAME = VALUE;
+
+#endif
+
+#endif  // marl_thread_local_h
diff --git a/third_party/marl/src/scheduler.cpp b/third_party/marl/src/scheduler.cpp
index 2f32582..f5e9df0 100644
--- a/third_party/marl/src/scheduler.cpp
+++ b/third_party/marl/src/scheduler.cpp
@@ -84,15 +84,13 @@
 ////////////////////////////////////////////////////////////////////////////////
 // Scheduler
 ////////////////////////////////////////////////////////////////////////////////
-thread_local Scheduler* Scheduler::bound = nullptr;
+MARL_INSTANTIATE_THREAD_LOCAL(Scheduler*, Scheduler::bound, nullptr);
 
 Scheduler* Scheduler::get() {
-  MSAN_UNPOISON(&bound, sizeof(Scheduler*));
   return bound;
 }
 
 void Scheduler::setBound(Scheduler* scheduler) {
-  MSAN_UNPOISON(&bound, sizeof(Scheduler*));
   bound = scheduler;
 }
 
@@ -354,7 +352,9 @@
 ////////////////////////////////////////////////////////////////////////////////
 // Scheduler::Worker
 ////////////////////////////////////////////////////////////////////////////////
-thread_local Scheduler::Worker* Scheduler::Worker::current = nullptr;
+MARL_INSTANTIATE_THREAD_LOCAL(Scheduler::Worker*,
+                              Scheduler::Worker::current,
+                              nullptr);
 
 Scheduler::Worker::Worker(Scheduler* scheduler, Mode mode, uint32_t id)
     : id(id),