diff --git a/src/unix/bsd/mod.rs b/src/unix/bsd/mod.rs
index ab256d1eb875281b621e6848537cce7214c753a2..1a7d22ab3414a7d20ae6c37508c36f17a56cf85b 100644
--- a/src/unix/bsd/mod.rs
+++ b/src/unix/bsd/mod.rs
@@ -491,6 +491,7 @@ extern {
                            oldset: *mut sigset_t) -> ::c_int;
     pub fn sem_open(name: *const ::c_char, oflag: ::c_int, ...) -> *mut sem_t;
     pub fn getgrnam(name: *const ::c_char) -> *mut ::group;
+    pub fn pthread_cancel(thread: ::pthread_t) -> ::c_int;
     pub fn pthread_kill(thread: ::pthread_t, sig: ::c_int) -> ::c_int;
     pub fn sem_unlink(name: *const ::c_char) -> ::c_int;
     pub fn daemon(nochdir: ::c_int, noclose: ::c_int) -> ::c_int;
diff --git a/src/unix/notbsd/linux/mod.rs b/src/unix/notbsd/linux/mod.rs
index 0841dd2e5a086e80dc0053d70d29b11bdf8febff..c88fe49cd388c0e462dd2609cbf75070a8472380 100644
--- a/src/unix/notbsd/linux/mod.rs
+++ b/src/unix/notbsd/linux/mod.rs
@@ -1411,6 +1411,7 @@ extern {
                            oldset: *mut sigset_t) -> ::c_int;
     pub fn sem_open(name: *const ::c_char, oflag: ::c_int, ...) -> *mut sem_t;
     pub fn getgrnam(name: *const ::c_char) -> *mut ::group;
+    pub fn pthread_cancel(thread: ::pthread_t) -> ::c_int;
     pub fn pthread_kill(thread: ::pthread_t, sig: ::c_int) -> ::c_int;
     pub fn sem_unlink(name: *const ::c_char) -> ::c_int;
     pub fn daemon(nochdir: ::c_int, noclose: ::c_int) -> ::c_int;