diff --git a/library/md.c b/library/md.c
index 882942e..92fe3a4 100644
--- a/library/md.c
+++ b/library/md.c
@@ -387,7 +387,7 @@
 
 void mbedtls_md_init( mbedtls_md_context_t *ctx )
 {
-    memset( ctx, 0, sizeof( mbedtls_md_context_t ) );
+    mbedtls_platform_memset( ctx, 0, sizeof( mbedtls_md_context_t ) );
 
 #if defined(MBEDTLS_MD_SINGLE_HASH)
     mbedtls_md_info_init( mbedtls_md_get_handle( ctx ),
@@ -563,8 +563,8 @@
     opad = (unsigned char *) ctx->hmac_ctx +
         mbedtls_md_info_block_size( md_info );
 
-    memset( ipad, 0x36, mbedtls_md_info_block_size( md_info ) );
-    memset( opad, 0x5C, mbedtls_md_info_block_size( md_info ) );
+    mbedtls_platform_memset( ipad, 0x36, mbedtls_md_info_block_size( md_info ) );
+    mbedtls_platform_memset( opad, 0x5C, mbedtls_md_info_block_size( md_info ) );
 
     for( i = 0; i < keylen; i++ )
     {