diff --git a/library/ssl_cookie.c b/library/ssl_cookie.c
index ec0814a..56e9bdd 100644
--- a/library/ssl_cookie.c
+++ b/library/ssl_cookie.c
@@ -40,7 +40,7 @@
 
 #include "mbedtls/ssl_cookie.h"
 #include "mbedtls/ssl_internal.h"
-#include "mbedtls/utils.h"
+#include "mbedtls/platform_util.h"
 
 #include <string.h>
 
@@ -97,7 +97,7 @@
     mbedtls_mutex_free( &ctx->mutex );
 #endif
 
-    mbedtls_zeroize( ctx, sizeof( mbedtls_ssl_cookie_ctx ) );
+    mbedtls_platform_zeroize( ctx, sizeof( mbedtls_ssl_cookie_ctx ) );
 }
 
 int mbedtls_ssl_cookie_setup( mbedtls_ssl_cookie_ctx *ctx,
@@ -118,7 +118,7 @@
     if( ret != 0 )
         return( ret );
 
-    mbedtls_zeroize( key, sizeof( key ) );
+    mbedtls_platform_zeroize( key, sizeof( key ) );
 
     return( 0 );
 }