diff --git a/library/rsa.c b/library/rsa.c
index 2185040..9e4a0f0 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -48,6 +48,7 @@
 #include "mbedtls/rsa.h"
 #include "mbedtls/rsa_internal.h"
 #include "mbedtls/oid.h"
+#include "mbedtls/utils.h"
 
 #include <string.h>
 
@@ -70,11 +71,6 @@
 
 #if !defined(MBEDTLS_RSA_ALT)
 
-/* 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;
-}
-
 #if defined(MBEDTLS_PKCS1_V15)
 /* constant-time buffer comparison */
 static inline int mbedtls_safer_memcmp( const void *a, const void *b, size_t n )