diff --git a/lib/std/c.zig b/lib/std/c.zig
index 43b3d7f317..0d8aa13dec 100644
--- a/lib/std/c.zig
+++ b/lib/std/c.zig
@@ -184,6 +184,7 @@ pub extern "c" fn futimens(fd: fd_t, times: *const [2]timespec) c_int;
 pub extern "c" fn pthread_create(noalias newthread: *pthread_t, noalias attr: ?*const pthread_attr_t, start_routine: extern fn (?*c_void) ?*c_void, noalias arg: ?*c_void) c_int;
 pub extern "c" fn pthread_attr_init(attr: *pthread_attr_t) c_int;
 pub extern "c" fn pthread_attr_setstack(attr: *pthread_attr_t, stackaddr: *c_void, stacksize: usize) c_int;
+pub extern "c" fn pthread_attr_setguardsize(attr: *pthread_attr_t, guardsize: usize) c_int;
 pub extern "c" fn pthread_attr_destroy(attr: *pthread_attr_t) c_int;
 pub extern "c" fn pthread_self() pthread_t;
 pub extern "c" fn pthread_join(thread: pthread_t, arg_return: ?*?*c_void) c_int;
diff --git a/lib/std/thread.zig b/lib/std/thread.zig
index f2b27caa97..6abe88c8cf 100644
--- a/lib/std/thread.zig
+++ b/lib/std/thread.zig
@@ -381,6 +381,11 @@ pub const Thread = struct {
                 mmap_slice.ptr + guard_end_offset,
                 stack_end_offset - guard_end_offset,
             ) == 0);
+            // Even though pthread's man pages state that the guard size is
+            // ignored when the stack address is explicitly given, on some
+            // plaforms such as NetBSD we still have to zero it to prevent
+            // random crashes in pthread_join calls
+            assert(c.pthread_attr_setguardsize(&attr, 0) == 0);
 
             const err = c.pthread_create(&thread_ptr.data.handle, &attr, MainFuncs.posixThreadMain, @intToPtr(*c_void, arg));
             switch (err) {