diff --git a/include/openssl/bio.h b/include/openssl/bio.h
index e224dd945..7fe88ec4e 100644
--- a/include/openssl/bio.h
+++ b/include/openssl/bio.h
@@ -276,7 +276,7 @@ void BIO_clear_flags(BIO *b, int flags);
  * BIO_CB_RETURN flag indicates if it is after the call
  */
 # define BIO_CB_RETURN   0x80
-# define BIO_CB_return(a) ((a)|BIO_CB_RETURN))
+# define BIO_CB_return(a) ((a)|BIO_CB_RETURN)
 # define BIO_cb_pre(a)   (!((a)&BIO_CB_RETURN))
 # define BIO_cb_post(a)  ((a)&BIO_CB_RETURN)