diff --git a/doc/man3/BIO_s_bio.pod b/doc/man3/BIO_s_bio.pod
index c3ed1397a7..dfafa351e4 100644
--- a/doc/man3/BIO_s_bio.pod
+++ b/doc/man3/BIO_s_bio.pod
@@ -144,7 +144,7 @@ without having to go through the SSL-interface.
  ...
  BIO_new_bio_pair(&internal_bio, 0, &network_bio, 0);
  SSL_set_bio(ssl, internal_bio, internal_bio);
- SSL_operations(); //e.g SSL_read and SSL_write
+ SSL_operations(); /* e.g SSL_read and SSL_write */
  ...
 
  application |   TLS-engine
diff --git a/doc/man3/CRYPTO_THREAD_run_once.pod b/doc/man3/CRYPTO_THREAD_run_once.pod
index 072790dc31..9a4df1992c 100644
--- a/doc/man3/CRYPTO_THREAD_run_once.pod
+++ b/doc/man3/CRYPTO_THREAD_run_once.pod
@@ -149,9 +149,9 @@ You can find out if OpenSSL was configured with thread support:
 
  #include <openssl/opensslconf.h>
  #if defined(OPENSSL_THREADS)
-     // thread support enabled
+     /* thread support enabled */
  #else
-     // no thread support
+     /* no thread support */
  #endif
 
 =head1 SEE ALSO