diff --git a/lib/std/c/dragonfly.zig b/lib/std/c/dragonfly.zig
index 80f583b497..4070ec9ea8 100644
--- a/lib/std/c/dragonfly.zig
+++ b/lib/std/c/dragonfly.zig
@@ -12,7 +12,7 @@ pub fn _errno() *c_int {
 pub extern "c" fn getdents(fd: c_int, buf_ptr: [*]u8, nbytes: usize) c_int;
 pub extern "c" fn sigaltstack(ss: ?*stack_t, old_ss: ?*stack_t) c_int;
 pub extern "c" fn getrandom(buf_ptr: [*]u8, buf_len: usize, flags: c_uint) isize;
-pub extern "c" fn pipe2(fds: *[2]fd_t, flags: u32) c_int;
+pub extern "c" fn pipe2(fds: *[2]fd_t, flags: std.c.O) c_int;
 pub extern "c" fn arc4random_buf(buf: [*]u8, len: usize) void;
 
 pub const dl_iterate_phdr_callback = *const fn (info: *dl_phdr_info, size: usize, data: ?*anyopaque) callconv(.C) c_int;
diff --git a/lib/std/c/emscripten.zig b/lib/std/c/emscripten.zig
index 0031132855..501fcb4386 100644
--- a/lib/std/c/emscripten.zig
+++ b/lib/std/c/emscripten.zig
@@ -147,7 +147,7 @@ pub const pwritev64 = std.c.pwritev;
 pub const setrlimit64 = std.c.setrlimit;
 
 pub extern "c" fn sigaltstack(ss: ?*stack_t, old_ss: ?*stack_t) c_int;
-pub extern "c" fn pipe2(fds: *[2]fd_t, flags: u32) c_int;
+pub extern "c" fn pipe2(fds: *[2]fd_t, flags: std.c.O) c_int;
 pub extern "c" fn getentropy(buffer: [*]u8, size: usize) c_int;
 
 pub const pthread_attr_t = extern struct {
diff --git a/lib/std/c/freebsd.zig b/lib/std/c/freebsd.zig
index d544bc92c8..561b940a81 100644
--- a/lib/std/c/freebsd.zig
+++ b/lib/std/c/freebsd.zig
@@ -15,7 +15,7 @@ pub extern "c" fn getrandom(buf_ptr: [*]u8, buf_len: usize, flags: c_uint) isize
 pub extern "c" fn pthread_getthreadid_np() c_int;
 pub extern "c" fn pthread_set_name_np(thread: std.c.pthread_t, name: [*:0]const u8) void;
 pub extern "c" fn pthread_get_name_np(thread: std.c.pthread_t, name: [*:0]u8, len: usize) void;
-pub extern "c" fn pipe2(fds: *[2]fd_t, flags: u32) c_int;
+pub extern "c" fn pipe2(fds: *[2]fd_t, flags: std.c.O) c_int;
 pub extern "c" fn arc4random_buf(buf: [*]u8, len: usize) void;
 
 pub extern "c" fn posix_memalign(memptr: *?*anyopaque, alignment: usize, size: usize) c_int;
diff --git a/lib/std/c/netbsd.zig b/lib/std/c/netbsd.zig
index 46997c5d75..3d78230290 100644
--- a/lib/std/c/netbsd.zig
+++ b/lib/std/c/netbsd.zig
@@ -15,7 +15,7 @@ pub extern "c" fn dl_iterate_phdr(callback: dl_iterate_phdr_callback, data: ?*an
 
 pub extern "c" fn _lwp_self() lwpid_t;
 
-pub extern "c" fn pipe2(fds: *[2]fd_t, flags: u32) c_int;
+pub extern "c" fn pipe2(fds: *[2]fd_t, flags: std.c.O) c_int;
 pub extern "c" fn arc4random_buf(buf: [*]u8, len: usize) void;
 
 pub extern "c" fn __stat50(path: [*:0]const u8, buf: *Stat) c_int;
@@ -59,7 +59,7 @@ pub extern "c" fn posix_memalign(memptr: *?*anyopaque, alignment: usize, size: u
 pub extern "c" fn __msync13(addr: *align(std.mem.page_size) const anyopaque, len: usize, flags: c_int) c_int;
 pub const msync = __msync13;
 
-const pthread_spin_t = switch (builtin.cpu.arch) {
+pub const pthread_spin_t = switch (builtin.cpu.arch) {
     .aarch64, .aarch64_be, .aarch64_32 => u8,
     .mips, .mipsel, .mips64, .mips64el => u32,
     .powerpc, .powerpc64, .powerpc64le => i32,
@@ -70,7 +70,7 @@ const pthread_spin_t = switch (builtin.cpu.arch) {
     else => @compileError("undefined pthread_spin_t for this arch"),
 };
 
-const padded_pthread_spin_t = switch (builtin.cpu.arch) {
+pub const padded_pthread_spin_t = switch (builtin.cpu.arch) {
     .x86, .x86_64 => u32,
     .sparc, .sparcel, .sparc64 => u32,
     else => pthread_spin_t,
diff --git a/lib/std/c/openbsd.zig b/lib/std/c/openbsd.zig
index 9b37aef05a..21f025f8f0 100644
--- a/lib/std/c/openbsd.zig
+++ b/lib/std/c/openbsd.zig
@@ -14,7 +14,7 @@ pub extern "c" fn dl_iterate_phdr(callback: dl_iterate_phdr_callback, data: ?*an
 pub extern "c" fn arc4random_buf(buf: [*]u8, len: usize) void;
 
 pub extern "c" fn getthrid() pid_t;
-pub extern "c" fn pipe2(fds: *[2]fd_t, flags: u32) c_int;
+pub extern "c" fn pipe2(fds: *[2]fd_t, flags: std.c.O) c_int;
 
 pub extern "c" fn getdents(fd: c_int, buf_ptr: [*]u8, nbytes: usize) c_int;
 pub extern "c" fn sigaltstack(ss: ?*stack_t, old_ss: ?*stack_t) c_int;
diff --git a/lib/std/c/solaris.zig b/lib/std/c/solaris.zig
index 7cb35697d4..ef64acd43b 100644
--- a/lib/std/c/solaris.zig
+++ b/lib/std/c/solaris.zig
@@ -14,7 +14,7 @@ pub extern "c" fn dl_iterate_phdr(callback: dl_iterate_phdr_callback, data: ?*an
 
 pub extern "c" fn getdents(fd: c_int, buf_ptr: [*]u8, nbytes: usize) usize;
 pub extern "c" fn sigaltstack(ss: ?*stack_t, old_ss: ?*stack_t) c_int;
-pub extern "c" fn pipe2(fds: *[2]fd_t, flags: u32) c_int;
+pub extern "c" fn pipe2(fds: *[2]fd_t, flags: std.c.O) c_int;
 pub extern "c" fn arc4random_buf(buf: [*]u8, len: usize) void;
 pub extern "c" fn posix_memalign(memptr: *?*anyopaque, alignment: usize, size: usize) c_int;
 pub extern "c" fn sysconf(sc: c_int) i64;
diff --git a/lib/std/fs/Dir.zig b/lib/std/fs/Dir.zig
index 5accd7b404..fa44ddfd09 100644
--- a/lib/std/fs/Dir.zig
+++ b/lib/std/fs/Dir.zig
@@ -174,7 +174,7 @@ pub const Iterator = switch (builtin.os.tag) {
                     self.end_index = @as(usize, @intCast(rc));
                 }
                 const bsd_entry = @as(*align(1) posix.system.dirent, @ptrCast(&self.buf[self.index]));
-                const next_index = self.index + bsd_entry.reclen;
+                const next_index = self.index + if (@hasDecl(posix.system.dirent, "reclen")) bsd_entry.reclen() else bsd_entry.reclen;
                 self.index = next_index;
 
                 const name = @as([*]u8, @ptrCast(&bsd_entry.name))[0..bsd_entry.namlen];