diff --git a/src/unix/haiku/mod.rs b/src/unix/haiku/mod.rs
index 3cf12800f6c0..db53784d9ab4 100644
--- a/src/unix/haiku/mod.rs
+++ b/src/unix/haiku/mod.rs
@@ -52,6 +52,9 @@ pub type Elf64_Xword = u64;
 pub type ENTRY = entry;
 pub type ACTION = ::c_int;
 
+pub type posix_spawnattr_t = *mut ::c_void;
+pub type posix_spawn_file_actions_t = *mut ::c_void;
+
 #[cfg_attr(feature = "extra_traits", derive(Debug))]
 pub enum timezone {}
 impl ::Copy for timezone {}
@@ -1438,6 +1441,13 @@ pub const LOG_SERIAL: ::c_int = 16 << 12;
 pub const LOG_PERROR: ::c_int = 32 << 12;
 pub const LOG_NOWAIT: ::c_int = 64 << 12;
 
+// spawn.h
+pub const POSIX_SPAWN_RESETIDS: ::c_int = 0x01;
+pub const POSIX_SPAWN_SETPGROUP: ::c_int = 0x02;
+pub const POSIX_SPAWN_SETSIGDEF: ::c_int = 0x10;
+pub const POSIX_SPAWN_SETSIGMASK: ::c_int = 0x20;
+pub const POSIX_SPAWN_SETSID: ::c_int = 0x40;
+
 const_fn! {
     {const} fn CMSG_ALIGN(len: usize) -> usize {
         len + ::mem::size_of::<usize>() - 1 & !(::mem::size_of::<usize>() - 1)
@@ -1888,6 +1898,74 @@ extern "C" {
 
     pub fn brk(addr: *mut ::c_void) -> ::c_int;
     pub fn sbrk(increment: ::intptr_t) -> *mut ::c_void;
+
+    pub fn posix_spawn(
+        pid: *mut ::pid_t,
+        path: *const ::c_char,
+        file_actions: *const ::posix_spawn_file_actions_t,
+        attrp: *const ::posix_spawnattr_t,
+        argv: *const *mut ::c_char,
+        envp: *const *mut ::c_char,
+    ) -> ::c_int;
+    pub fn posix_spawnp(
+        pid: *mut ::pid_t,
+        file: *const ::c_char,
+        file_actions: *const ::posix_spawn_file_actions_t,
+        attrp: *const ::posix_spawnattr_t,
+        argv: *const *mut ::c_char,
+        envp: *const *mut ::c_char,
+    ) -> ::c_int;
+
+    pub fn posix_spawn_file_actions_init(file_actions: *mut posix_spawn_file_actions_t) -> ::c_int;
+    pub fn posix_spawn_file_actions_destroy(
+        file_actions: *mut posix_spawn_file_actions_t,
+    ) -> ::c_int;
+    pub fn posix_spawn_file_actions_addopen(
+        file_actions: *mut posix_spawn_file_actions_t,
+        fildes: ::c_int,
+        path: *const ::c_char,
+        oflag: ::c_int,
+        mode: ::mode_t,
+    ) -> ::c_int;
+    pub fn posix_spawn_file_actions_addclose(
+        file_actions: *mut posix_spawn_file_actions_t,
+        fildes: ::c_int,
+    ) -> ::c_int;
+    pub fn posix_spawn_file_actions_adddup2(
+        file_actions: *mut posix_spawn_file_actions_t,
+        fildes: ::c_int,
+        newfildes: ::c_int,
+    ) -> ::c_int;
+
+    pub fn posix_spawnattr_init(attr: *mut posix_spawnattr_t) -> ::c_int;
+    pub fn posix_spawnattr_destroy(attr: *mut posix_spawnattr_t) -> ::c_int;
+    pub fn posix_spawnattr_getflags(
+        attr: *const posix_spawnattr_t,
+        _flags: *mut ::c_short,
+    ) -> ::c_int;
+    pub fn posix_spawnattr_setflags(attr: *mut posix_spawnattr_t, flags: ::c_short) -> ::c_int;
+    pub fn posix_spawnattr_getpgroup(
+        attr: *const posix_spawnattr_t,
+        _pgroup: *mut ::pid_t,
+    ) -> ::c_int;
+    pub fn posix_spawnattr_setpgroup(attr: *mut posix_spawnattr_t, pgroup: ::pid_t) -> ::c_int;
+    pub fn posix_spawnattr_getsigdefault(
+        attr: *const posix_spawnattr_t,
+        sigdefault: *mut ::sigset_t,
+    ) -> ::c_int;
+    pub fn posix_spawnattr_setsigdefault(
+        attr: *mut posix_spawnattr_t,
+        sigdefault: *const ::sigset_t,
+    ) -> ::c_int;
+    pub fn posix_spawnattr_getsigmask(
+        attr: *const posix_spawnattr_t,
+        _sigmask: *mut ::sigset_t,
+    ) -> ::c_int;
+    pub fn posix_spawnattr_setsigmask(
+        attr: *mut posix_spawnattr_t,
+        sigmask: *const ::sigset_t,
+    ) -> ::c_int;
+
 }
 
 #[link(name = "bsd")]