diff --git a/mkuutils.rs b/mkuutils.rs
index c263297de..0cd4ed112 100644
--- a/mkuutils.rs
+++ b/mkuutils.rs
@@ -40,7 +40,7 @@ fn main() {
             }
             _ => {
                 crates.push_str(format!("extern crate {};\n", prog).as_slice());
-                util_map.push_str(format!("map.insert(\"{prog}\", {prog}::uumain as fn(Vec<String>) -> int);\n", prog = prog).as_slice());
+                util_map.push_str(format!("map.insert(\"{prog}\", {prog}::uumain as fn(Vec<String>) -> isize);\n", prog = prog).as_slice());
             }
         }
     }
diff --git a/src/basename/basename.rs b/src/basename/basename.rs
index 0f9f304cb..71892a516 100644
--- a/src/basename/basename.rs
+++ b/src/basename/basename.rs
@@ -22,7 +22,7 @@ mod util;
 static NAME: &'static str = "basename";
 static VERSION: &'static str = "1.0.0";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = strip_dir(args[0].as_slice());
 
     //
diff --git a/src/cat/cat.rs b/src/cat/cat.rs
index 7c15a1a2b..33b410cd5 100644
--- a/src/cat/cat.rs
+++ b/src/cat/cat.rs
@@ -19,7 +19,7 @@ use std::io::stdio::{stdout_raw, stdin_raw, stderr};
 use std::io::{IoResult};
 use std::ptr::{copy_nonoverlapping_memory};
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].as_slice();
     let opts = [
         getopts::optflag("A", "show-all", "equivalent to -vET"),
diff --git a/src/cp/cp.rs b/src/cp/cp.rs
index 765063d17..a9d8e4f5b 100644
--- a/src/cp/cp.rs
+++ b/src/cp/cp.rs
@@ -31,7 +31,7 @@ pub enum Mode {
 
 impl Copy for Mode {}
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let opts = [
         optflag("h", "help", "display this help and exit"),
         optflag("", "version", "output version information and exit"),
diff --git a/src/cut/cut.rs b/src/cut/cut.rs
index feaefc4aa..3a934b37a 100644
--- a/src/cut/cut.rs
+++ b/src/cut/cut.rs
@@ -447,7 +447,7 @@ fn cut_files(mut filenames: Vec<String>, mode: Mode) -> int {
     exit_code
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let opts = [
         optopt("b", "bytes", "select only these bytes", "LIST"),
         optopt("c", "characters", "select only these characters", "LIST"),
diff --git a/src/dirname/dirname.rs b/src/dirname/dirname.rs
index 8b25bdb67..6f88a8268 100644
--- a/src/dirname/dirname.rs
+++ b/src/dirname/dirname.rs
@@ -15,7 +15,7 @@ use std::io::print;
 
 static VERSION: &'static str = "1.0.0";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
     let opts = [
         getopts::optflag("z", "zero", "separate output with NUL rather than newline"),
diff --git a/src/du/du.rs b/src/du/du.rs
index c56ccde0c..d7619f2cf 100644
--- a/src/du/du.rs
+++ b/src/du/du.rs
@@ -89,7 +89,7 @@ fn du(path: &Path, mut my_stat: Stat,
     stats
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].as_slice();
     let opts = [
         // In task
diff --git a/src/echo/echo.rs b/src/echo/echo.rs
index 176fbd5e3..017a83b2b 100644
--- a/src/echo/echo.rs
+++ b/src/echo/echo.rs
@@ -162,7 +162,7 @@ fn print_version() {
     println!("echo version: {}", VERSION);
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let mut options = EchoOptions {
         newline: false,
         escape: false
diff --git a/src/env/env.rs b/src/env/env.rs
index dec94d810..cc67f1ab4 100644
--- a/src/env/env.rs
+++ b/src/env/env.rs
@@ -51,7 +51,7 @@ fn print_env(null: bool) {
     }
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let prog = args[0].as_slice();
 
     // to handle arguments the same way than GNU env, we can't use getopts
diff --git a/src/expand/expand.rs b/src/expand/expand.rs
index 6ba026e92..b65105d54 100644
--- a/src/expand/expand.rs
+++ b/src/expand/expand.rs
@@ -72,7 +72,7 @@ impl Options {
     }
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let opts = [
         getopts::optflag("i", "initial", "do not convert tabs after non blanks"),
         getopts::optopt("t", "tabs", "have tabs NUMBER characters apart, not 8", "NUMBER"),
diff --git a/src/factor/factor.rs b/src/factor/factor.rs
index 935c1c645..b66bf2055 100644
--- a/src/factor/factor.rs
+++ b/src/factor/factor.rs
@@ -63,7 +63,7 @@ fn print_factors_str(num_str: &str) {
     print_factors(num);
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].as_slice();
     let opts = [
         getopts::optflag("h", "help", "show this help message"),
diff --git a/src/false/false.rs b/src/false/false.rs
index 5fdc0022e..68c3ed16e 100644
--- a/src/false/false.rs
+++ b/src/false/false.rs
@@ -9,6 +9,6 @@
  * file that was distributed with this source code.
  */
 
-pub fn uumain(_: Vec<String>) -> int  {
+pub fn uumain(_: Vec<String>) -> isize {
     1
 }
diff --git a/src/fmt/fmt.rs b/src/fmt/fmt.rs
index db5dd748b..2021ef7a0 100644
--- a/src/fmt/fmt.rs
+++ b/src/fmt/fmt.rs
@@ -54,7 +54,7 @@ struct FmtOptions {
     tabwidth        : uint,
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
 
     let opts = [
         getopts::optflag("c", "crown-margin", "First and second line of paragraph may have different indentations, in which case the first line's indentation is preserved, and each subsequent line's indentation matches the second line."),
diff --git a/src/fold/fold.rs b/src/fold/fold.rs
index 79bc76f96..c7c6deaeb 100644
--- a/src/fold/fold.rs
+++ b/src/fold/fold.rs
@@ -23,7 +23,7 @@ mod util;
 static NAME: &'static str = "fold";
 static VERSION: &'static str = "1.0.0";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let (args, obs_width) = handle_obsolete(args.as_slice());
     let program = args[0].clone();
 
diff --git a/src/groups/groups.rs b/src/groups/groups.rs
index 7db857155..29c3a755b 100644
--- a/src/groups/groups.rs
+++ b/src/groups/groups.rs
@@ -23,7 +23,7 @@ use c_types::{get_pw_from_args, group};
 static NAME: &'static str = "groups";
 static VERSION: &'static str = "1.0.0";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
 
     let options = [
diff --git a/src/head/head.rs b/src/head/head.rs
index 7e1bbd2ed..965bd2364 100644
--- a/src/head/head.rs
+++ b/src/head/head.rs
@@ -26,7 +26,7 @@ mod util;
 
 static NAME: &'static str = "head";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let mut line_count = 10u;
     let mut byte_count = 0u;
 
diff --git a/src/hostid/hostid.rs b/src/hostid/hostid.rs
index f4902fa5a..63ac56798 100644
--- a/src/hostid/hostid.rs
+++ b/src/hostid/hostid.rs
@@ -48,7 +48,7 @@ extern {
     pub fn gethostid() -> c_long;
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
 
     let opts = [
         optflag("", "help", "display this help and exit"),
diff --git a/src/hostname/hostname.rs b/src/hostname/hostname.rs
index 5ad247404..65674873a 100644
--- a/src/hostname/hostname.rs
+++ b/src/hostname/hostname.rs
@@ -41,7 +41,7 @@ extern {
     fn sethostname(name: *const libc::c_char, namelen: libc::size_t) -> libc::c_int;
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = &args[0];
 
     let options = [
diff --git a/src/id/id.rs b/src/id/id.rs
index 442957779..4b7b97126 100644
--- a/src/id/id.rs
+++ b/src/id/id.rs
@@ -83,7 +83,7 @@ extern {
 
 static NAME: &'static str = "id";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let args_t = args.tail();
 
     let options = [
diff --git a/src/kill/kill.rs b/src/kill/kill.rs
index abd556da7..f42176237 100644
--- a/src/kill/kill.rs
+++ b/src/kill/kill.rs
@@ -52,7 +52,7 @@ pub enum Mode {
 
 impl Copy for Mode {}
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let opts = [
         optflag("h", "help", "display this help and exit"),
         optflag("V", "version", "output version information and exit"),
diff --git a/src/link/link.rs b/src/link/link.rs
index 121aad5b7..4f0da2ede 100644
--- a/src/link/link.rs
+++ b/src/link/link.rs
@@ -21,7 +21,7 @@ mod util;
 static NAME : &'static str = "link";
 static VERSION : &'static str = "1.0.0";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let opts = [
         getopts::optflag("h", "help", "display this help and exit"),
         getopts::optflag("V", "version", "output version information and exit"),
diff --git a/src/logname/logname.rs b/src/logname/logname.rs
index f5a36ca6c..ddd8d332c 100644
--- a/src/logname/logname.rs
+++ b/src/logname/logname.rs
@@ -45,7 +45,7 @@ fn version() {
     println!("{} {}", NAME, VERSION);
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
 
     //
diff --git a/src/mkdir/mkdir.rs b/src/mkdir/mkdir.rs
index e21490292..120c5bd2d 100644
--- a/src/mkdir/mkdir.rs
+++ b/src/mkdir/mkdir.rs
@@ -26,7 +26,7 @@ static VERSION: &'static str = "1.0.0";
 /**
  * Handles option parsing
  */
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
 
     let opts = [
         // Linux-specific options, not implemented
diff --git a/src/mv/mv.rs b/src/mv/mv.rs
index 396d15f8a..e2d68ae0b 100644
--- a/src/mv/mv.rs
+++ b/src/mv/mv.rs
@@ -61,7 +61,7 @@ pub enum BackupMode {
 
 impl Copy for BackupMode {}
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].as_slice();
     let opts = [
         optflagopt("",  "backup", "make a backup of each existing destination file", "CONTROL"),
diff --git a/src/nice/nice.rs b/src/nice/nice.rs
index 4573e8eb4..126f2b35b 100644
--- a/src/nice/nice.rs
+++ b/src/nice/nice.rs
@@ -32,7 +32,7 @@ extern {
     fn setpriority(which: c_int, who: c_int, prio: c_int) -> c_int;
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let opts = [
         getopts::optopt("n", "adjustment", "add N to the niceness (default is 10)", "N"),
         getopts::optflag("h", "help", "display this help and exit"),
diff --git a/src/nl/nl.rs b/src/nl/nl.rs
index 9273e72f6..747ae0bbe 100644
--- a/src/nl/nl.rs
+++ b/src/nl/nl.rs
@@ -73,7 +73,7 @@ enum NumberFormat {
     RightZero,
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let possible_options = [
         optopt("b", "body-numbering", "use STYLE for numbering body lines", "STYLE"),
         optopt("d", "section-delimiter", "use CC for separating logical pages", "CC"),
diff --git a/src/nohup/nohup.rs b/src/nohup/nohup.rs
index 8792f526f..78d5c51a1 100644
--- a/src/nohup/nohup.rs
+++ b/src/nohup/nohup.rs
@@ -35,7 +35,7 @@ extern {
 #[cfg(any(target_os = "linux", target_os = "freebsd"))]
 unsafe fn _vprocmgr_detach_from_console(_: u32) -> *const libc::c_int { std::ptr::null() }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = &args[0];
 
     let options = [
diff --git a/src/nproc/nproc.rs b/src/nproc/nproc.rs
index 589165288..3f1b26f06 100644
--- a/src/nproc/nproc.rs
+++ b/src/nproc/nproc.rs
@@ -20,7 +20,7 @@ static VERSION : &'static str = "0.0.0";
 #[macro_use]
 mod util;
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let opts = [
         getopts::optflag("", "all", "print the number of cores available to the system"),
         getopts::optopt("", "ignore", "ignore up to N cores", "N"),
diff --git a/src/printenv/printenv.rs b/src/printenv/printenv.rs
index 70b7c028f..054353d91 100644
--- a/src/printenv/printenv.rs
+++ b/src/printenv/printenv.rs
@@ -23,7 +23,7 @@ mod util;
 
 static NAME: &'static str = "printenv";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
     let opts = [
         getopts::optflag("0", "null", "end each output line with 0 byte rather than newline"),
diff --git a/src/pwd/pwd.rs b/src/pwd/pwd.rs
index 52af689aa..508112ab2 100644
--- a/src/pwd/pwd.rs
+++ b/src/pwd/pwd.rs
@@ -21,7 +21,7 @@ mod util;
 static NAME: &'static str = "pwd";
 static VERSION: &'static str = "1.0.0";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
     let opts = [
         getopts::optflag("", "help", "display this help and exit"),
diff --git a/src/realpath/realpath.rs b/src/realpath/realpath.rs
index a42d03507..80a7c08cf 100644
--- a/src/realpath/realpath.rs
+++ b/src/realpath/realpath.rs
@@ -19,7 +19,7 @@ use getopts::{optflag, getopts, usage};
 static NAME: &'static str = "realpath";
 static VERSION: &'static str = "1.0.0";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = &args[0];
     let options = [
         optflag("h", "help", "Show help and exit"),
diff --git a/src/relpath/relpath.rs b/src/relpath/relpath.rs
index 2d2337a45..8b03c4779 100644
--- a/src/relpath/relpath.rs
+++ b/src/relpath/relpath.rs
@@ -19,7 +19,7 @@ use getopts::{optflag, optopt, getopts, usage};
 static NAME: &'static str = "relpath";
 static VERSION: &'static str = "1.0.0";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = &args[0];
     let options = [
         optflag("h", "help", "Show help and exit"),
diff --git a/src/rm/rm.rs b/src/rm/rm.rs
index 1e22b4a91..ec45e221e 100644
--- a/src/rm/rm.rs
+++ b/src/rm/rm.rs
@@ -30,7 +30,7 @@ impl Copy for InteractiveMode {}
 
 static NAME: &'static str = "rm";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
 
     // TODO: make getopts support -R in addition to -r
diff --git a/src/rmdir/rmdir.rs b/src/rmdir/rmdir.rs
index 06fa2700a..e16501042 100644
--- a/src/rmdir/rmdir.rs
+++ b/src/rmdir/rmdir.rs
@@ -21,7 +21,7 @@ mod util;
 
 static NAME: &'static str = "rmdir";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
 
     let opts = [
diff --git a/src/seq/seq.rs b/src/seq/seq.rs
index 1b72f0123..9e4cf2c25 100644
--- a/src/seq/seq.rs
+++ b/src/seq/seq.rs
@@ -145,7 +145,7 @@ fn print_version() {
     println!("seq 1.0.0\n");
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
     let mut options = SeqOptions {
         separator: "\n".to_string(),
diff --git a/src/sleep/sleep.rs b/src/sleep/sleep.rs
index b6d83db67..21efa36e5 100644
--- a/src/sleep/sleep.rs
+++ b/src/sleep/sleep.rs
@@ -25,7 +25,7 @@ mod time;
 
 static NAME: &'static str = "sleep";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
 
     let opts = [
diff --git a/src/split/split.rs b/src/split/split.rs
index f5a26f4dd..c0a154ad7 100644
--- a/src/split/split.rs
+++ b/src/split/split.rs
@@ -23,7 +23,7 @@ mod util;
 static NAME: &'static str = "split";
 static VERSION: &'static str = "1.0.0";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let opts = [
         getopts::optopt("a", "suffix-length", "use suffixes of length N (default 2)", "N"),
         getopts::optopt("b", "bytes", "put SIZE bytes per output file", "SIZE"),
diff --git a/src/sync/sync.rs b/src/sync/sync.rs
index 8f007dfce..daad1ba4c 100644
--- a/src/sync/sync.rs
+++ b/src/sync/sync.rs
@@ -138,7 +138,7 @@ mod platform {
     }
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = &args[0];
 
     let options = [
diff --git a/src/tail/tail.rs b/src/tail/tail.rs
index ae27794be..532f263cc 100644
--- a/src/tail/tail.rs
+++ b/src/tail/tail.rs
@@ -29,7 +29,7 @@ mod util;
 static NAME: &'static str = "tail";
 static VERSION: &'static str = "0.0.1";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let mut beginning = false;
     let mut lines = true;
     let mut byte_count = 0u;
diff --git a/src/tee/tee.rs b/src/tee/tee.rs
index e2f290caa..bbb1bc865 100644
--- a/src/tee/tee.rs
+++ b/src/tee/tee.rs
@@ -21,7 +21,7 @@ use getopts::{getopts, optflag, usage};
 static NAME: &'static str = "tee";
 static VERSION: &'static str = "1.0.0";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     match options(args.as_slice()).and_then(exec) {
         Ok(_) => 0,
         Err(_) => 1
diff --git a/src/test/test.rs b/src/test/test.rs
index 7bab557ac..72dcc6a6d 100644
--- a/src/test/test.rs
+++ b/src/test/test.rs
@@ -18,7 +18,7 @@ use std::str::{from_utf8};
 static NAME: &'static str = "test";
 
 // TODO: decide how to handle non-UTF8 input for all the utils
-pub fn uumain(_: Vec<String>) -> int {
+pub fn uumain(_: Vec<String>) -> isize {
     let args = args_as_bytes();
     let args: Vec<&[u8]> = args.iter().map(|a| a.as_slice()).collect();
     if args.len() == 0 {
diff --git a/src/timeout/timeout.rs b/src/timeout/timeout.rs
index 2ce570618..3462b8cb3 100644
--- a/src/timeout/timeout.rs
+++ b/src/timeout/timeout.rs
@@ -34,7 +34,7 @@ static VERSION: &'static str = "1.0.0";
 
 static ERR_EXIT_STATUS: int = 125;
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
 
     let opts = [
diff --git a/src/touch/touch.rs b/src/touch/touch.rs
index 07a37aad9..f32c1c72f 100644
--- a/src/touch/touch.rs
+++ b/src/touch/touch.rs
@@ -22,7 +22,7 @@ mod util;
 static NAME: &'static str = "touch";
 static VERSION: &'static str = "1.0.0";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let opts = [
         getopts::optflag("a", "",               "change only the access time"),
         getopts::optflag("c", "no-create",      "do not create any files"),
diff --git a/src/tr/tr.rs b/src/tr/tr.rs
index e8fb644a5..da862aa6c 100644
--- a/src/tr/tr.rs
+++ b/src/tr/tr.rs
@@ -158,7 +158,7 @@ fn usage(opts: &[OptGroup]) {
     print(getopts::usage("Translate or delete characters.", opts).as_slice());
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let opts = [
         getopts::optflag("c", "complement", "use the complement of SET1"),
         getopts::optflag("C", "", "same as -c"),
diff --git a/src/true/true.rs b/src/true/true.rs
index df9d7f2b2..f43220f82 100644
--- a/src/true/true.rs
+++ b/src/true/true.rs
@@ -9,6 +9,6 @@
  * file that was distributed with this source code.
  */
 
-pub fn uumain(_: Vec<String>) -> int {
+pub fn uumain(_: Vec<String>) -> isize {
     0
 }
diff --git a/src/truncate/truncate.rs b/src/truncate/truncate.rs
index 7b76fe4fb..76cac158a 100644
--- a/src/truncate/truncate.rs
+++ b/src/truncate/truncate.rs
@@ -33,7 +33,7 @@ enum TruncateMode {
 
 static NAME: &'static str = "truncate";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
 
     let opts = [
diff --git a/src/tsort/tsort.rs b/src/tsort/tsort.rs
index 198c19933..340db735f 100644
--- a/src/tsort/tsort.rs
+++ b/src/tsort/tsort.rs
@@ -23,7 +23,7 @@ mod util;
 static NAME: &'static str = "tsort";
 static VERSION: &'static str = "1.0.0";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let opts = [
         getopts::optflag("h", "help", "display this help and exit"),
         getopts::optflag("V", "version", "output version information and exit"),
diff --git a/src/tty/tty.rs b/src/tty/tty.rs
index d7d0aaf2d..fd366c861 100644
--- a/src/tty/tty.rs
+++ b/src/tty/tty.rs
@@ -33,7 +33,7 @@ extern {
 
 static NAME: &'static str = "tty";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let options = [
         optflag("s", "silent", "print nothing, only return an exit status")
     ];
diff --git a/src/uname/uname.rs b/src/uname/uname.rs
index c944891b4..7e4b44e12 100644
--- a/src/uname/uname.rs
+++ b/src/uname/uname.rs
@@ -55,7 +55,7 @@ unsafe fn getuname() -> utsrust {
 
 static NAME: &'static str = "uname";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].as_slice();
     let opts = [
         getopts::optflag("h", "help", "display this help and exit"),
diff --git a/src/unexpand/unexpand.rs b/src/unexpand/unexpand.rs
index fb1393760..65fa1927e 100644
--- a/src/unexpand/unexpand.rs
+++ b/src/unexpand/unexpand.rs
@@ -72,7 +72,7 @@ impl Options {
     }
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let opts = [
         getopts::optflag("a", "all", "convert all blanks, instead of just initial blanks"),
         getopts::optflag("", "first-only", "convert only leading sequences of blanks (overrides -a)"),
diff --git a/src/uniq/uniq.rs b/src/uniq/uniq.rs
index 2560c27ac..1246234f0 100644
--- a/src/uniq/uniq.rs
+++ b/src/uniq/uniq.rs
@@ -117,7 +117,7 @@ fn opt_parsed<T: FromStr>(opt_name: &str, matches: &getopts::Matches) -> Option<
     })
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program_path = Path::new(args[0].clone());
     let program = program_path.filename_str().unwrap_or(NAME);
 
diff --git a/src/unlink/unlink.rs b/src/unlink/unlink.rs
index 1895c9902..100e5c493 100644
--- a/src/unlink/unlink.rs
+++ b/src/unlink/unlink.rs
@@ -24,7 +24,7 @@ mod util;
 
 static NAME: &'static str = "unlink";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
     let opts = [
         getopts::optflag("h", "help", "display this help and exit"),
diff --git a/src/uptime/uptime.rs b/src/uptime/uptime.rs
index 2fd2eb2ea..06720acc0 100644
--- a/src/uptime/uptime.rs
+++ b/src/uptime/uptime.rs
@@ -53,7 +53,7 @@ unsafe extern fn utmpxname(_file: *const c_char) -> c_int {
     0
 }
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
     let opts = [
         getopts::optflag("v", "version", "output version information and exit"),
diff --git a/src/users/users.rs b/src/users/users.rs
index 39bc99220..6fa4adec4 100644
--- a/src/users/users.rs
+++ b/src/users/users.rs
@@ -51,7 +51,7 @@ unsafe extern fn utmpxname(_file: *const libc::c_char) -> libc::c_int {
 
 static NAME: &'static str = "users";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].as_slice();
     let opts = [
         getopts::optflag("h", "help", "display this help and exit"),
diff --git a/src/wc/wc.rs b/src/wc/wc.rs
index 9c041f180..84498e02a 100644
--- a/src/wc/wc.rs
+++ b/src/wc/wc.rs
@@ -35,7 +35,7 @@ struct Result {
 
 static NAME: &'static str = "wc";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
     let opts = [
         getopts::optflag("c", "bytes", "print the byte counts"),
diff --git a/src/whoami/whoami.rs b/src/whoami/whoami.rs
index dbea93b70..bcb81bb7d 100644
--- a/src/whoami/whoami.rs
+++ b/src/whoami/whoami.rs
@@ -62,7 +62,7 @@ mod platform {
 
 static NAME: &'static str = "whoami";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].as_slice();
     let opts = [
         getopts::optflag("h", "help", "display this help and exit"),
diff --git a/src/yes/yes.rs b/src/yes/yes.rs
index e7143f42b..07634c229 100644
--- a/src/yes/yes.rs
+++ b/src/yes/yes.rs
@@ -22,7 +22,7 @@ mod util;
 
 static NAME: &'static str = "yes";
 
-pub fn uumain(args: Vec<String>) -> int {
+pub fn uumain(args: Vec<String>) -> isize {
     let program = args[0].clone();
     let opts = [
         getopts::optflag("h", "help", "display this help and exit"),