diff --git a/libc-test/build.rs b/libc-test/build.rs
index ba428fc7303d1..b42402f08a229 100644
--- a/libc-test/build.rs
+++ b/libc-test/build.rs
@@ -2148,6 +2148,9 @@ fn test_freebsd(target: &str) {
             // Added in FreeBSD 14
             "LIO_READV" | "LIO_WRITEV" | "LIO_VECTORED" if Some(14) > freebsd_ver => true,
 
+            // Added in FreeBSD 13
+            "FIOSSHMLPGCNF" if Some(13) > freebsd_ver => true,
+
             _ => false,
         }
     });
@@ -2178,6 +2181,8 @@ fn test_freebsd(target: &str) {
 
             // `sockcred2` is not available in FreeBSD 12.
             "sockcred2" if Some(13) > freebsd_ver => true,
+            // `shm_largepage_conf` was introduced in FreeBSD 13.
+            "shm_largepage_conf" if Some(13) > freebsd_ver => true,
 
             _ => false,
         }
diff --git a/libc-test/semver/freebsd.txt b/libc-test/semver/freebsd.txt
index 5bba5f307028e..e74355f1e5a07 100644
--- a/libc-test/semver/freebsd.txt
+++ b/libc-test/semver/freebsd.txt
@@ -341,6 +341,7 @@ FIONWRITE
 FIOSEEKDATA
 FIOSEEKHOLE
 FIOSETOWN
+FIOSSHMLPGCNF
 FLUSHO
 FOPEN_MAX
 F_DUP2FD
diff --git a/src/unix/bsd/freebsdlike/freebsd/mod.rs b/src/unix/bsd/freebsdlike/freebsd/mod.rs
index 42a71b21332ed..4ed525968e069 100644
--- a/src/unix/bsd/freebsdlike/freebsd/mod.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/mod.rs
@@ -992,6 +992,12 @@ s! {
         pub _flags: u32,
         pub _clockid: u32,
     }
+
+    pub struct shm_largepage_conf {
+        pub psind: ::c_int,
+        pub alloc_policy: ::c_int,
+        __pad: [::c_int; 10],
+    }
 }
 
 s_no_extra_traits! {
@@ -2254,6 +2260,7 @@ pub const FIONWRITE: ::c_ulong = 0x40046677;
 pub const FIONSPACE: ::c_ulong = 0x40046676;
 pub const FIOSEEKDATA: ::c_ulong = 0xc0086661;
 pub const FIOSEEKHOLE: ::c_ulong = 0xc0086662;
+pub const FIOSSHMLPGCNF: ::c_ulong = 0x80306664;
 
 pub const JAIL_API_VERSION: u32 = 2;
 pub const JAIL_CREATE: ::c_int = 0x01;