diff --git a/src/swab.rs b/src/swab.rs
index 4dc86de..6afed28 100644
--- a/src/swab.rs
+++ b/src/swab.rs
@@ -38,17 +38,17 @@ use strerror::StrError;
 
 fn oserr(argv0: &str, e: Error) -> ExitCode {
 	eprintln!("{}: {}", argv0, e.strerror());
-	ExitCode::from(EX_OSERR as u8)
+	ExitCode::from(EX_OSERR)
 }
 
 fn ioerr(argv0: &str, e: Error) -> ExitCode {
 	eprintln!("{}: {}", argv0, e.strerror());
-	ExitCode::from(EX_IOERR as u8)
+	ExitCode::from(EX_IOERR)
 }
 
 fn usage(s: &str) -> ExitCode {
 	eprintln!("Usage: {} [-w word_size]", s);
-	ExitCode::from(EX_USAGE as u8)
+	ExitCode::from(EX_USAGE)
 }
 
 fn main() -> ExitCode {
@@ -88,7 +88,7 @@ fn main() -> ExitCode {
 
 	loop {
 		match input.read(&mut buf) {
-			Ok(0) => break ExitCode::from(EX_OK as u8), // read nothing; bye
+			Ok(0) => break ExitCode::from(EX_OK), // read nothing; bye
 			Ok(v) if v == wordsize => { // read full block; swab
 				let (left, right) = buf.split_at(v/2);