diff --git a/library/cipher.c b/library/cipher.c
index 7369f48..1b2e569 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -33,6 +33,7 @@
 
 #include "mbedtls/cipher.h"
 #include "mbedtls/cipher_internal.h"
+#include "mbedtls/utils.h"
 
 #include <stdlib.h>
 #include <string.h>
@@ -60,11 +61,6 @@
 #define MBEDTLS_CIPHER_MODE_STREAM
 #endif
 
-/* Implementation that should never be optimized out by the compiler */
-static void mbedtls_zeroize( void *v, size_t n ) {
-    volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
-}
-
 static int supported_init = 0;
 
 const int *mbedtls_cipher_list( void )