diff --git a/lib/std/c/dragonfly.zig b/lib/std/c/dragonfly.zig
index bfe7806c14..26c0b34abe 100644
--- a/lib/std/c/dragonfly.zig
+++ b/lib/std/c/dragonfly.zig
@@ -12,6 +12,7 @@ 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 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 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;
 pub extern "c" fn dl_iterate_phdr(callback: dl_iterate_phdr_callback, data: ?*anyopaque) c_int;