diff --git a/libafl/src/bolts/core_affinity.rs b/libafl/src/bolts/core_affinity.rs
index efe6e1f1d9..38ce99efa2 100644
--- a/libafl/src/bolts/core_affinity.rs
+++ b/libafl/src/bolts/core_affinity.rs
@@ -716,18 +716,14 @@ mod netbsd {
     use alloc::vec::Vec;
     use std::thread::available_parallelism;
 
-    use libc::{_cpuset, pthread_self, pthread_setaffinity_np};
+    use libc::{
+        _cpuset, _cpuset_create, _cpuset_destroy, _cpuset_set, _cpuset_size, pthread_self,
+        pthread_setaffinity_np,
+    };
 
     use super::CoreId;
     use crate::Error;
 
-    extern "C" {
-        fn _cpuset_create() -> *mut _cpuset;
-        fn _cpuset_destroy(c: *mut _cpuset);
-        fn _cpuset_set(i: usize, c: *mut _cpuset) -> i32;
-        fn _cpuset_size(c: *const _cpuset) -> usize;
-    }
-
     #[allow(trivial_numeric_casts)]
     pub fn get_core_ids() -> Result<Vec<CoreId>, Error> {
         Ok((0..(usize::from(available_parallelism()?)))
@@ -739,7 +735,7 @@ mod netbsd {
     pub fn set_for_current(core_id: CoreId) -> Result<(), Error> {
         let set = new_cpuset();
 
-        unsafe { _cpuset_set(core_id.id, set) };
+        unsafe { _cpuset_set(core_id.id as u64, set) };
         // Set the current thread's core affinity.
         let result = unsafe {
             pthread_setaffinity_np(