diff --git a/include/mimalloc-atomic.h b/include/mimalloc-atomic.h
index 05a9f01c..55b11f7a 100644
--- a/include/mimalloc-atomic.h
+++ b/include/mimalloc-atomic.h
@@ -52,9 +52,6 @@ static inline void* mi_atomic_exchange_ptr(volatile void** p, void* exchange) {
 }
 
 
-
-#define mi_atomic_locked(mutex) for(bool _mheld = mi_mutex_lock(mutex); _mheld; _mheld = mi_mutex_unlock(mutex))
-
 #ifdef _MSC_VER
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
@@ -176,22 +173,4 @@ static inline uintptr_t mi_atomic_exchange(volatile uintptr_t* p, uintptr_t exch
 
 #endif
 
-// Light weight mutex for low contention situations
-typedef struct mi_mutex_s {
-  volatile uint32_t value;
-} mi_mutex_t;
-
-static inline bool mi_mutex_lock(mi_mutex_t* mutex) {
-  while(!mi_atomic_compare_exchange32(&mutex->value, 1, 0)) {
-    mi_atomic_yield();
-  }
-  return true;
-}
-
-static inline bool mi_mutex_unlock(mi_mutex_t* mutex) {
-  mutex->value = 0;
-  return false;
-}
-
-
 #endif // __MIMALLOC_ATOMIC_H
diff --git a/test/main.c b/test/main.c
index 8b2b2cd4..b148f712 100644
--- a/test/main.c
+++ b/test/main.c
@@ -11,6 +11,17 @@ void test_heap(void* p_out) {
   //mi_heap_delete(heap); mi_free(p1); mi_free(p2);
 }
 
+void test_large() {
+  const size_t N = 1000;
+
+  for (size_t i = 0; i < N; ++i) {
+    size_t sz = 1ull << 21;
+    char* a = mi_mallocn_tp(char,sz);
+    for (size_t k = 0; k < sz; k++) { a[k] = 'x'; }
+    mi_free(a);
+  }
+}
+
 int main() {
   void* p1 = mi_malloc(16);
   void* p2 = mi_malloc(1000000);
@@ -27,9 +38,9 @@ int main() {
   p2 = mi_malloc_aligned(160,24);
   mi_free(p2);
   mi_free(p1);
-  
+  //test_large();
+
   mi_collect(true);
   mi_stats_print(NULL);
   return 0;
 }
-