diff --git a/include/openssl/bio.h b/include/openssl/bio.h
index 54a833c275577af028cf2fed828daa395a0f97b1..d8d8ac403184cc436f073e49c934cf6bb97633e1 100644
--- a/include/openssl/bio.h
+++ b/include/openssl/bio.h
@@ -735,7 +735,8 @@ void BIO_copy_next_retry(BIO *b);
  */
 
 # define __bio_h__attr__(x)
-# if defined(__GNUC__) && defined(__STDC_VERSION__)
+# if defined(__GNUC__) && defined(__STDC_VERSION__) \
+    && !defined(__APPLE__)
     /*
      * Because we support the 'z' modifier, which made its appearance in C99,
      * we can't use __attribute__ with pre C99 dialects.