diff --git a/include/openssl/chacha.h b/include/openssl/chacha.h
index 3d035e6..61deb8e 100644
--- a/include/openssl/chacha.h
+++ b/include/openssl/chacha.h
@@ -22,16 +22,16 @@
 #endif
 
 
-/* CRYPTO_chacha_20 encrypts |in_len| bytes from |in| with the given key and
- * nonce and writes the result to |out|. If |in| and |out| alias, they must be
- * equal. The initial block counter is specified by |counter|. */
+// CRYPTO_chacha_20 encrypts |in_len| bytes from |in| with the given key and
+// nonce and writes the result to |out|. If |in| and |out| alias, they must be
+// equal. The initial block counter is specified by |counter|.
 OPENSSL_EXPORT void CRYPTO_chacha_20(uint8_t *out, const uint8_t *in,
                                      size_t in_len, const uint8_t key[32],
                                      const uint8_t nonce[12], uint32_t counter);
 
 
 #if defined(__cplusplus)
-}  /* extern C */
+}  // extern C
 #endif
 
-#endif  /* OPENSSL_HEADER_CHACHA_H */
+#endif  // OPENSSL_HEADER_CHACHA_H