diff --git a/library/cipher.c b/library/cipher.c
index 1b2e569..a5cd61c 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -33,7 +33,7 @@
 
 #include "mbedtls/cipher.h"
 #include "mbedtls/cipher_internal.h"
-#include "mbedtls/utils.h"
+#include "mbedtls/platform_util.h"
 
 #include <stdlib.h>
 #include <string.h>
@@ -137,7 +137,8 @@
 #if defined(MBEDTLS_CMAC_C)
     if( ctx->cmac_ctx )
     {
-       mbedtls_zeroize( ctx->cmac_ctx, sizeof( mbedtls_cmac_context_t ) );
+       mbedtls_platform_zeroize( ctx->cmac_ctx,
+                                 sizeof( mbedtls_cmac_context_t ) );
        mbedtls_free( ctx->cmac_ctx );
     }
 #endif
@@ -145,7 +146,7 @@
     if( ctx->cipher_ctx )
         ctx->cipher_info->base->ctx_free_func( ctx->cipher_ctx );
 
-    mbedtls_zeroize( ctx, sizeof(mbedtls_cipher_context_t) );
+    mbedtls_platform_zeroize( ctx, sizeof(mbedtls_cipher_context_t) );
 }
 
 int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx, const mbedtls_cipher_info_t *cipher_info )