diff --git a/src/uptime/uptime.rs b/src/uptime/uptime.rs
index 06720acc0..5e127c853 100644
--- a/src/uptime/uptime.rs
+++ b/src/uptime/uptime.rs
@@ -17,6 +17,7 @@ extern crate getopts;
 extern crate libc;
 extern crate "time" as rtime;
 
+use std::ffi::CString;
 use std::mem::transmute;
 use std::io::{print, File};
 use std::ptr::null;
@@ -105,11 +106,9 @@ fn print_loadavg() {
 
 #[cfg(unix)]
 fn process_utmpx() -> (Option<time_t>, uint) {
-    DEFAULT_FILE.with_c_str(|filename| {
-        unsafe {
-            utmpxname(filename);
-        }
-    });
+    unsafe {
+        utmpxname(CString::from_slice(DEFAULT_FILE.as_bytes()).as_ptr());
+    }
 
     let mut nusers = 0;
     let mut boot_time = None;
@@ -172,7 +171,7 @@ fn get_uptime(boot_time: Option<time_t>) -> i64 {
         _ => return match boot_time {
                 Some(t) => {
                     let now = rtime::get_time().sec;
-                    let time = t.to_i64().unwrap();
+                    let time = t as i64;
                     ((now - time) * 100) as i64 // Return in ms
                 },
                 _ => -1
diff --git a/src/users/users.rs b/src/users/users.rs
index 6fa4adec4..57782e61c 100644
--- a/src/users/users.rs
+++ b/src/users/users.rs
@@ -17,7 +17,7 @@
 extern crate getopts;
 extern crate libc;
 
-use std::ffi::c_str_to_bytes;
+use std::ffi::{CString, c_str_to_bytes};
 use std::io::print;
 use std::mem;
 use std::ptr;
@@ -89,11 +89,9 @@ pub fn uumain(args: Vec<String>) -> isize {
 }
 
 fn exec(filename: &str) {
-    filename.with_c_str(|filename| {
-        unsafe {
-            utmpxname(filename);
-        }
-    });
+    unsafe {
+        utmpxname(CString::from_slice(filename.as_bytes()).as_ptr());
+    }
 
     let mut users = vec!();
 
diff --git a/src/whoami/whoami.rs b/src/whoami/whoami.rs
index bcb81bb7d..78422f5d2 100644
--- a/src/whoami/whoami.rs
+++ b/src/whoami/whoami.rs
@@ -35,9 +35,7 @@ mod platform {
         let passwd: *const c_passwd = getpwuid(geteuid());
 
         let pw_name: *const libc::c_char = (*passwd).pw_name;
-        let name = String::from_raw_buf(pw_name as *const u8);
-
-        name
+        String::from_utf8_lossy(::std::ffi::c_str_to_bytes(&pw_name)).to_string()
     }
 }
 
@@ -56,7 +54,7 @@ mod platform {
         if !GetUserNameA(buffer.as_mut_ptr(), &mut (buffer.len() as libc::uint32_t)) == 0 {
             crash!(1, "username is too long");
         }
-        String::from_raw_buf(buffer.as_ptr() as *const u8)
+        String::from_utf8_lossy(::std::ffi::c_str_to_bytes(&buffer.as_ptr())).to_string()
     }
 }