diff --git a/libc-test/semver/apple.txt b/libc-test/semver/apple.txt
index b697b893ae7a3..b43f28eaabf76 100644
--- a/libc-test/semver/apple.txt
+++ b/libc-test/semver/apple.txt
@@ -1349,6 +1349,7 @@ TAB2
 TAB3
 TABDLY
 TCP_FASTOPEN
+TCP_FASTOPEN_FORCE_ENABLE
 TCP_KEEPALIVE
 TCP_KEEPCNT
 TCP_KEEPINTVL
diff --git a/src/unix/bsd/apple/mod.rs b/src/unix/bsd/apple/mod.rs
index 519a99346504d..d6d713576bbd9 100644
--- a/src/unix/bsd/apple/mod.rs
+++ b/src/unix/bsd/apple/mod.rs
@@ -3657,6 +3657,8 @@ pub const TCP_KEEPINTVL: ::c_int = 0x101;
 pub const TCP_KEEPCNT: ::c_int = 0x102;
 /// Enable/Disable TCP Fastopen on this socket
 pub const TCP_FASTOPEN: ::c_int = 0x105;
+/// Disable/Enable TCP Fastopen backoff mechanism.
+pub const TCP_FASTOPEN_FORCE_ENABLE: ::c_int = 0x218;
 
 pub const SOL_LOCAL: ::c_int = 0;