diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 5737bb2d90dc6bf80356c7b7eff8034f15f55f6b..eed7943395b979d941a78ef21304b12c4aa6f689 100755
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -29,6 +29,7 @@
 #ifndef MBEDTLS_CONFIG_H
 #define MBEDTLS_CONFIG_H
 #include <stdio.h>
+#include <stdlib.h>
 #if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_DEPRECATE)
 #define _CRT_SECURE_NO_DEPRECATE 1
 #endif
@@ -177,7 +178,7 @@
  *
  * Enable this layer to allow use of alternative memory allocators.
  */
-// #define MBEDTLS_PLATFORM_MEMORY
+#define MBEDTLS_PLATFORM_MEMORY
 
 /**
  * \def MBEDTLS_PLATFORM_NO_STD_FUNCTIONS
@@ -196,7 +197,7 @@
  * Uncomment to prevent default assignment of standard functions in the
  * platform layer.
  */
-// #define MBEDTLS_PLATFORM_NO_STD_FUNCTIONS
+#define MBEDTLS_PLATFORM_NO_STD_FUNCTIONS
 
 /**
  * \def MBEDTLS_PLATFORM_EXIT_ALT
@@ -1160,7 +1161,7 @@
  *
  * Uncomment this macro to disable the built-in platform entropy functions.
  */
-#define MBEDTLS_NO_PLATFORM_ENTROPY
+// #define MBEDTLS_NO_PLATFORM_ENTROPY
 
 /**
  * \def MBEDTLS_ENTROPY_FORCE_SHA256
@@ -3076,8 +3077,8 @@
 
 /* Platform options */
 // #define MBEDTLS_PLATFORM_STD_MEM_HDR   <stdlib.h> /**< Header to include if MBEDTLS_PLATFORM_NO_STD_FUNCTIONS is defined. Don't define if no header is needed. */
-// #define MBEDTLS_PLATFORM_STD_CALLOC        calloc /**< Default allocator to use, can be undefined */
-// #define MBEDTLS_PLATFORM_STD_FREE            free /**< Default free to use, can be undefined */
+ #define MBEDTLS_PLATFORM_STD_CALLOC        calloc /**< Default allocator to use, can be undefined */
+ #define MBEDTLS_PLATFORM_STD_FREE            free /**< Default free to use, can be undefined */
 // #define MBEDTLS_PLATFORM_STD_EXIT            exit /**< Default exit to use, can be undefined */
 // #define MBEDTLS_PLATFORM_STD_TIME            time /**< Default time to use, can be undefined. MBEDTLS_HAVE_TIME must be enabled */
 // #define MBEDTLS_PLATFORM_STD_FPRINTF      fprintf /**< Default fprintf to use, can be undefined */