diff --git a/src/unistd.rs b/src/unistd.rs
index 25cff4a791..cfb2e8d626 100644
--- a/src/unistd.rs
+++ b/src/unistd.rs
@@ -1401,6 +1401,7 @@ pub fn setgid(gid: Gid) -> Result<()> {
 /// Set the user identity used for filesystem checks
 ///
 /// See also [setfsuid(2)](http://man7.org/linux/man-pages/man2/setfsuid.2.html)
+#[cfg(target_os = "linux")]
 #[inline]
 pub fn setfsuid(uid: Uid) -> Result<()> {
     let res = unsafe { libc::setfsuid(uid.into()) };
@@ -1411,6 +1412,7 @@ pub fn setfsuid(uid: Uid) -> Result<()> {
 /// Set the group identity used for filesystem checks
 ///
 /// See also [setfsgid(2)](http://man7.org/linux/man-pages/man2/setfsgid.2.html)
+#[cfg(target_os = "linux")]
 #[inline]
 pub fn setfsgid(gid: Gid) -> Result<()> {
     let res = unsafe { libc::setfsgid(gid.into()) };