diff --git a/src/memory/DefaultAllocator.h b/src/memory/DefaultAllocator.h
index 5ff94895..c8432438 100644
--- a/src/memory/DefaultAllocator.h
+++ b/src/memory/DefaultAllocator.h
@@ -29,6 +29,7 @@
 // Libraries
 #include "memory/MemoryAllocator.h"
 #include <cstdlib>
+#include <mutex>
 
 /// ReactPhysics3D namespace
 namespace reactphysics3d {
@@ -39,6 +40,11 @@ namespace reactphysics3d {
  */
 class DefaultAllocator : public MemoryAllocator {
 
+    protected:
+
+        /// Mutex
+        std::mutex mMutex;
+
     public:
 
         /// Destructor
@@ -50,11 +56,19 @@ class DefaultAllocator : public MemoryAllocator {
         /// Allocate memory of a given size (in bytes) and return a pointer to the
         /// allocated memory.
         virtual void* allocate(size_t size) override {
+
+            // Lock the method with a mutex
+            std::lock_guard<std::mutex> lock(mMutex);
+
             return malloc(size);
         }
 
         /// Release previously allocated memory.
         virtual void release(void* pointer, size_t size) override {
+
+            // Lock the method with a mutex
+            std::lock_guard<std::mutex> lock(mMutex);
+
             free(pointer);
         }
 };
diff --git a/src/memory/DefaultPoolAllocator.cpp b/src/memory/DefaultPoolAllocator.cpp
index 39f84eee..fddcc2f8 100644
--- a/src/memory/DefaultPoolAllocator.cpp
+++ b/src/memory/DefaultPoolAllocator.cpp
@@ -100,6 +100,9 @@ DefaultPoolAllocator::~DefaultPoolAllocator() {
 // allocated memory.
 void* DefaultPoolAllocator::allocate(size_t size) {
 
+    // Lock the method with a mutex
+    std::lock_guard<std::mutex> lock(mMutex);
+
     // We cannot allocate zero bytes
     if (size == 0) return nullptr;
 
@@ -173,6 +176,9 @@ void* DefaultPoolAllocator::allocate(size_t size) {
 // Release previously allocated memory.
 void DefaultPoolAllocator::release(void* pointer, size_t size) {
 
+    // Lock the method with a mutex
+    std::lock_guard<std::mutex> lock(mMutex);
+
     // Cannot release a 0-byte allocated memory
     if (size == 0) return;
 
diff --git a/src/memory/DefaultPoolAllocator.h b/src/memory/DefaultPoolAllocator.h
index 172a3c6c..8610da0c 100644
--- a/src/memory/DefaultPoolAllocator.h
+++ b/src/memory/DefaultPoolAllocator.h
@@ -29,6 +29,7 @@
 // Libraries
 #include "configuration.h"
 #include "MemoryAllocator.h"
+#include <mutex>
 
 /// ReactPhysics3D namespace
 namespace reactphysics3d {
@@ -101,6 +102,9 @@ class DefaultPoolAllocator : public MemoryAllocator {
         /// True if the mMapSizeToHeapIndex array has already been initialized
         static bool isMapSizeToHeadIndexInitialized;
 
+        /// Mutex
+        std::mutex mMutex;
+
         /// Pointers to the first free memory unit for each heap
         MemoryUnit* mFreeMemoryUnits[NB_HEAPS];
 
diff --git a/src/memory/DefaultSingleFrameAllocator.cpp b/src/memory/DefaultSingleFrameAllocator.cpp
index de76ce57..3037488e 100644
--- a/src/memory/DefaultSingleFrameAllocator.cpp
+++ b/src/memory/DefaultSingleFrameAllocator.cpp
@@ -54,6 +54,9 @@ DefaultSingleFrameAllocator::~DefaultSingleFrameAllocator() {
 // allocated memory.
 void* DefaultSingleFrameAllocator::allocate(size_t size) {
 
+    // Lock the method with a mutex
+    std::lock_guard<std::mutex> lock(mMutex);
+
     // Check that there is enough remaining memory in the buffer
     if (mCurrentOffset + size > mTotalSizeBytes) {
 
@@ -77,6 +80,9 @@ void* DefaultSingleFrameAllocator::allocate(size_t size) {
 // Release previously allocated memory.
 void DefaultSingleFrameAllocator::release(void* pointer, size_t size) {
 
+    // Lock the method with a mutex
+    std::lock_guard<std::mutex> lock(mMutex);
+
     // If allocated memory is not within the single frame allocation range
     char* p = static_cast<char*>(pointer);
     if (p < mMemoryBufferStart || p > mMemoryBufferStart + mTotalSizeBytes) {
diff --git a/src/memory/DefaultSingleFrameAllocator.h b/src/memory/DefaultSingleFrameAllocator.h
index 65641129..1ad98769 100644
--- a/src/memory/DefaultSingleFrameAllocator.h
+++ b/src/memory/DefaultSingleFrameAllocator.h
@@ -29,6 +29,7 @@
 // Libraries
 #include "MemoryAllocator.h"
 #include "configuration.h"
+#include <mutex>
 
 /// ReactPhysics3D namespace
 namespace reactphysics3d {
@@ -52,7 +53,11 @@ class DefaultSingleFrameAllocator : public SingleFrameAllocator {
         static const size_t INIT_SINGLE_FRAME_ALLOCATOR_NB_BYTES = 1048576; // 1Mb
 
         // -------------------- Attributes -------------------- //
-		/// Cached memory allocator used on construction
+
+        /// Mutex
+        std::mutex mMutex;
+
+        /// Cached memory allocator used on construction
 		MemoryAllocator* mBaseMemoryAllocator;
 
         /// Total size (in bytes) of memory of the allocator