diff --git a/src/unix/bsd/freebsdlike/freebsd/freebsd13/mod.rs b/src/unix/bsd/freebsdlike/freebsd/freebsd13/mod.rs
index af381c05..8cb475d9 100644
--- a/src/unix/bsd/freebsdlike/freebsd/freebsd13/mod.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/freebsd13/mod.rs
@@ -231,6 +231,7 @@ extern "C" {
     pub fn fdatasync(fd: ::c_int) -> ::c_int;
 
     pub fn getrandom(buf: *mut ::c_void, buflen: ::size_t, flags: ::c_uint) -> ::ssize_t;
+    pub fn getentropy(buf: *mut ::c_void, buflen: ::size_t) -> ::c_int;
     pub fn elf_aux_info(aux: ::c_int, buf: *mut ::c_void, buflen: ::c_int) -> ::c_int;
 }