diff --git a/crypto/rand/rand.c b/crypto/rand/rand.c
index daebdf0..0d146a8 100644
--- a/crypto/rand/rand.c
+++ b/crypto/rand/rand.c
@@ -17,6 +17,7 @@
 #include <limits.h>
 #include <string.h>
 
+#include <openssl/chacha.h>
 #include <openssl/mem.h>
 
 #include "internal.h"
@@ -69,10 +70,6 @@
   OPENSSL_free(state);
 }
 
-extern void CRYPTO_chacha_20(uint8_t *out, const uint8_t *in, size_t in_len,
-                             const uint8_t key[32], const uint8_t nonce[8],
-                             size_t counter);
-
 int RAND_bytes(uint8_t *buf, size_t len) {
   if (len == 0) {
     return 1;