diff --git a/libc-test/semver/netbsd.txt b/libc-test/semver/netbsd.txt
index a2b72aba69872..4d1e7cf0d93f5 100644
--- a/libc-test/semver/netbsd.txt
+++ b/libc-test/semver/netbsd.txt
@@ -595,6 +595,7 @@ MAP_HASSEMAPHORE
 MAP_NORESERVE
 MAP_REMAPDUP
 MAP_RENAME
+MAP_STACK
 MAP_WIRED
 MAXFREQ
 MAXPHASE
diff --git a/src/unix/bsd/netbsdlike/netbsd/mod.rs b/src/unix/bsd/netbsdlike/netbsd/mod.rs
index 474698af0c064..cf383798f69a2 100644
--- a/src/unix/bsd/netbsdlike/netbsd/mod.rs
+++ b/src/unix/bsd/netbsdlike/netbsd/mod.rs
@@ -1296,6 +1296,7 @@ pub const MAP_RENAME: ::c_int = 0x20;
 pub const MAP_NORESERVE: ::c_int = 0x40;
 pub const MAP_HASSEMAPHORE: ::c_int = 0x200;
 pub const MAP_WIRED: ::c_int = 0x800;
+pub const MAP_STACK: ::c_int = 0x2000;
 // mremap flag
 pub const MAP_REMAPDUP: ::c_int = 0x004;