diff --git a/crypto/rand/rand.c b/crypto/rand/rand.c
index 924b54b..8076b78 100644
--- a/crypto/rand/rand.c
+++ b/crypto/rand/rand.c
@@ -152,8 +152,8 @@
   if (len >= sizeof(state->partial_block)) {
     size_t remaining = len;
     while (remaining > 0) {
-      // kMaxBytesPerCall is only 2GB, while ChaCha can handle 256GB. But this
-      // is sufficient and easier on 32-bit.
+      /* kMaxBytesPerCall is only 2GB, while ChaCha can handle 256GB. But this
+       * is sufficient and easier on 32-bit. */
       static const size_t kMaxBytesPerCall = 0x80000000;
       size_t todo = remaining;
       if (todo > kMaxBytesPerCall) {