diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 1381c1f..d9835b3 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -3798,7 +3798,7 @@
 
 /* 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_CALLOC        calloc /**< Default allocator to use, can be undefined. Please note that it should zeroize the buffer after allocation. */
 //#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 */