diff --git a/CHANGELOG.md b/CHANGELOG.md
index 75fc82def4..f79a1cbebf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,6 +33,8 @@ This project adheres to [Semantic Versioning](https://semver.org/).
   (#[1615](https://github.com/nix-rust/nix/pull/1615))
 - Added `getresuid`, `setresuid`, `getresgid`, and `setresgid` on DragonFly, FreeBSD, and OpenBSD.
   (#[1628](https://github.com/nix-rust/nix/pull/1628))
+- Added `MAP_FIXED_NOREPLACE` on Linux.
+  (#[TODO](https://github.com/nix-rust/nix/pull/TODO))
 
 ### Changed
 ### Fixed
diff --git a/src/sys/mman.rs b/src/sys/mman.rs
index 7302a65a2f..523b468341 100644
--- a/src/sys/mman.rs
+++ b/src/sys/mman.rs
@@ -43,6 +43,10 @@ libc_bitflags!{
         MAP_PRIVATE;
         /// Place the mapping at exactly the address specified in `addr`.
         MAP_FIXED;
+        /// Place the mapping at exactly the address specified in `addr`, but never clobber an existing range.
+        #[cfg(target_os = "linux")]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
+        MAP_FIXED_NOREPLACE;
         /// To be used with `MAP_FIXED`, to forbid the system
         /// to select a different address than the one specified.
         #[cfg(target_os = "freebsd")]