diff --git a/src/resource.rs b/src/resource.rs
index 99025d4..039f48d 100644
--- a/src/resource.rs
+++ b/src/resource.rs
@@ -1,6 +1,6 @@
 //! Set and get program scheduling priority
 use errno::{Errno, errno, set_errno};
-use libc::{PRIO_PROCESS,PRIO_PGRP,PRIO_USER,setpriority,getpriority, id_t};
+use libc::{PRIO_PROCESS,PRIO_PGRP,PRIO_USER,setpriority,getpriority,id_t,c_int};
 
 /// Which identifier type to use (`pid`, `gid`, or `uid`)
 #[allow(missing_docs)]
@@ -27,7 +27,7 @@ pub fn set_priority(which: Which, who: i32, priority: i32) -> Result<(), ()> {
         Which::User => PRIO_USER,
     };
 
-    match unsafe { setpriority(c_which as u32, who as id_t, priority) } {
+    match unsafe { setpriority(c_which as c_int, who as id_t, priority) } {
         0 => Ok(()),
         _ => Err(()),
     }
@@ -47,7 +47,7 @@ pub fn get_priority(which: Which, who: i32) -> Result<i32, ()> {
     };
 
     set_errno(Errno(0));
-    let priority = unsafe { getpriority(c_which as u32, who as id_t) };
+    let priority = unsafe { getpriority(c_which as c_int, who as id_t) };
     match errno().0 {
         0 => Ok(priority),
         _ => Err(()),