diff --git a/pkg/hacl/Makefile b/pkg/hacl/Makefile
index cf3f0d5634..59ffa9408d 100644
--- a/pkg/hacl/Makefile
+++ b/pkg/hacl/Makefile
@@ -6,7 +6,6 @@ PKG_LICENSE=MIT
 .PHONY: all
 
 all: git-download
-	@cp $(RIOTBASE)/pkg/hacl/src/* $(PKG_BUILDDIR)
 	"$(MAKE)" -C $(PKG_BUILDDIR) -f $(CURDIR)/Makefile.$(PKG_NAME)
 
 include $(RIOTBASE)/pkg/pkg.mk
diff --git a/pkg/hacl/patches/0001-RIOT-Use-RIOT-random_bytes-function-instead-of-rando.patch b/pkg/hacl/patches/0001-RIOT-Use-RIOT-random_bytes-function-instead-of-rando.patch
new file mode 100644
index 0000000000..6a189cf050
--- /dev/null
+++ b/pkg/hacl/patches/0001-RIOT-Use-RIOT-random_bytes-function-instead-of-rando.patch
@@ -0,0 +1,43 @@
+From 23c0d7e698ec5a31d65d7da172891f6aabad39d5 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Joakim=20Nohlg=C3=A5rd?= <joakim.nohlgard@eistec.se>
+Date: Tue, 15 May 2018 13:17:38 +0200
+Subject: [PATCH] RIOT: Use RIOT random_bytes function instead of randombytes
+
+---
+ haclnacl.c | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+diff --git a/haclnacl.c b/haclnacl.c
+index e9bf635309..072a2db6b3 100644
+--- a/haclnacl.c
++++ b/haclnacl.c
+@@ -28,7 +28,7 @@
+ #include "NaCl.h"
+ 
+ 
+-extern void randombytes(uint8_t *bytes, uint64_t bytes_len);
++#include "random.h"
+ 
+ 
+ /* HACL* Primitives and Constructions */
+@@ -93,7 +93,7 @@ int crypto_auth_verify(const unsigned char *tag, const unsigned char *input, uns
+ 
+ 
+ int crypto_box_keypair(unsigned char *pk, unsigned char *sk){
+-  randombytes(sk, 32);
++  random_bytes(sk, 32);
+   uint8_t basepoint[32] = {9};
+   curve25519_scalarmult(pk, sk, basepoint);
+   return 0;
+@@ -241,7 +241,7 @@ int crypto_sign_open(unsigned char *unsigned_msg, unsigned long long *unsigned_m
+ }
+ 
+ int crypto_sign_keypair(uint8_t pk[32], uint8_t sk[64]){
+-  randombytes(sk, 32 * sizeof(uint8_t));
++  random_bytes(sk, 32 * sizeof(uint8_t));
+   Hacl_Ed25519_secret_to_public(pk, sk);
+   for (int i = 0; i < 32; i++) sk[32+i] = pk[i];
+   return 0;
+-- 
+2.17.0
+
diff --git a/pkg/hacl/src/randombytes.c b/pkg/hacl/src/randombytes.c
deleted file mode 100644
index e318dfa3b2..0000000000
--- a/pkg/hacl/src/randombytes.c
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * Copyright (C) 2016 Kaspar Schleiser <kaspar@schleiser.de>
- *
- * This file is subject to the terms and conditions of the GNU Lesser
- * General Public License v2.1. See the file LICENSE in the top level
- * directory for more details.
- */
-
-#include <stdint.h>
-
-#include "random.h"
-
-
-void randombytes(uint8_t *target, uint64_t n)
-{
-    /* HACL* (haclnacl.c) needs uint64_t as "n" parameter, random provides uint32 */
-    random_bytes(target, n);
-}