diff --git a/src/sys/socket/mod.rs b/src/sys/socket/mod.rs
index e26e327d78..247cbe4d5e 100644
--- a/src/sys/socket/mod.rs
+++ b/src/sys/socket/mod.rs
@@ -290,12 +290,18 @@ libc_bitflags! {
     /// Additional socket options
     pub struct SockFlag: c_int {
         /// Set non-blocking mode on the new socket
+        ///
+        /// Note: macOS supports `NONBLOCK` through separate call to `fcntl`,
+        /// e.g. `nix::fcntl::fcntl(fd, F_SETFL(O_NONBLOCK))`
         #[cfg(any(linux_android,
                   freebsdlike,
                   netbsdlike,
                   solarish))]
         SOCK_NONBLOCK;
         /// Set close-on-exec on the new descriptor
+        ///
+        /// Note: macOS supports `CLOEXEC` through separate call to `fcntl`,
+        /// e.g. `nix::fcntl::fcntl(fd, F_SETFL(O_CLOEXEC))`
         #[cfg(any(linux_android,
                   freebsdlike,
                   netbsdlike,