diff --git a/src/uu/uptime/src/uptime.rs b/src/uu/uptime/src/uptime.rs
index 240a35371..e001a64a8 100644
--- a/src/uu/uptime/src/uptime.rs
+++ b/src/uu/uptime/src/uptime.rs
@@ -6,7 +6,8 @@
 // spell-checker:ignore getloadavg behaviour loadavg uptime upsecs updays upmins uphours boottime nusers utmpxname gettime clockid
 
 use chrono::{Local, TimeZone, Utc};
-use clap::ArgMatches;
+#[cfg(unix)]
+use std::ffi::OsString;
 use std::io;
 use thiserror::Error;
 use uucore::error::{UError, UResult};
@@ -44,14 +45,10 @@ pub enum UptimeError {
     // io::Error wrapper
     #[error("couldn't get boot time: {0}")]
     IoErr(#[from] io::Error),
-
     #[error("couldn't get boot time: Is a directory")]
     TargetIsDir,
-
     #[error("couldn't get boot time: Illegal seek")]
     TargetIsFifo,
-    #[error("extra operand '{0}'")]
-    ExtraOperandError(String),
 }
 
 impl UError for UptimeError {
@@ -64,41 +61,22 @@ impl UError for UptimeError {
 pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     let matches = uu_app().try_get_matches_from(args)?;
 
-    #[cfg(windows)]
-    return default_uptime(&matches);
-
     #[cfg(unix)]
-    {
-        use std::ffi::OsString;
-        use uucore::error::set_exit_code;
-        use uucore::show_error;
+    let file_path = matches.get_one::<OsString>(options::PATH);
+    #[cfg(windows)]
+    let file_path = None;
 
-        let argument = matches.get_many::<OsString>(options::PATH);
-
-        // Switches to default uptime behaviour if there is no argument
-        if argument.is_none() {
-            return default_uptime(&matches);
-        }
-        let mut arg_iter = argument.unwrap();
-
-        let file_path = arg_iter.next().unwrap();
-        if let Some(path) = arg_iter.next() {
-            // Uptime doesn't attempt to calculate boot time if there is extra arguments.
-            // Its a fatal error
-            show_error!(
-                "{}",
-                UptimeError::ExtraOperandError(path.to_owned().into_string().unwrap())
-            );
-            set_exit_code(1);
-            return Ok(());
-        }
-
-        uptime_with_file(file_path)
+    if matches.get_flag(options::SINCE) {
+        uptime_since()
+    } else if let Some(path) = file_path {
+        uptime_with_file(path)
+    } else {
+        default_uptime()
     }
 }
 
 pub fn uu_app() -> Command {
-    Command::new(uucore::util_name())
+    let cmd = Command::new(uucore::util_name())
         .version(uucore::crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
@@ -109,18 +87,20 @@ pub fn uu_app() -> Command {
                 .long(options::SINCE)
                 .help("system up since")
                 .action(ArgAction::SetTrue),
-        )
-        .arg(
-            Arg::new(options::PATH)
-                .help("file to search boot time from")
-                .action(ArgAction::Append)
-                .value_parser(ValueParser::os_string())
-                .value_hint(ValueHint::AnyPath),
-        )
+        );
+    #[cfg(unix)]
+    cmd.arg(
+        Arg::new(options::PATH)
+            .help("file to search boot time from")
+            .action(ArgAction::Set)
+            .num_args(0..=1)
+            .value_parser(ValueParser::os_string())
+            .value_hint(ValueHint::AnyPath),
+    )
 }
 
 #[cfg(unix)]
-fn uptime_with_file(file_path: &std::ffi::OsString) -> UResult<()> {
+fn uptime_with_file(file_path: &OsString) -> UResult<()> {
     use std::fs;
     use std::os::unix::fs::FileTypeExt;
     use uucore::error::set_exit_code;
@@ -212,27 +192,29 @@ fn uptime_with_file(file_path: &std::ffi::OsString) -> UResult<()> {
     Ok(())
 }
 
+fn uptime_since() -> UResult<()> {
+    #[cfg(unix)]
+    #[cfg(not(target_os = "openbsd"))]
+    let (boot_time, _) = process_utmpx(None);
+
+    #[cfg(target_os = "openbsd")]
+    let uptime = get_uptime(None)?;
+    #[cfg(unix)]
+    #[cfg(not(target_os = "openbsd"))]
+    let uptime = get_uptime(boot_time)?;
+    #[cfg(target_os = "windows")]
+    let uptime = get_uptime(None)?;
+
+    let initial_date = Local
+        .timestamp_opt(Utc::now().timestamp() - uptime, 0)
+        .unwrap();
+    println!("{}", initial_date.format("%Y-%m-%d %H:%M:%S"));
+
+    Ok(())
+}
+
 /// Default uptime behaviour i.e. when no file argument is given.
-fn default_uptime(matches: &ArgMatches) -> UResult<()> {
-    if matches.get_flag(options::SINCE) {
-        #[cfg(unix)]
-        #[cfg(not(target_os = "openbsd"))]
-        let (boot_time, _) = process_utmpx(None);
-
-        #[cfg(target_os = "openbsd")]
-        let uptime = get_uptime(None)?;
-        #[cfg(unix)]
-        #[cfg(not(target_os = "openbsd"))]
-        let uptime = get_uptime(boot_time)?;
-        #[cfg(target_os = "windows")]
-        let uptime = get_uptime(None)?;
-        let initial_date = Local
-            .timestamp_opt(Utc::now().timestamp() - uptime, 0)
-            .unwrap();
-        println!("{}", initial_date.format("%Y-%m-%d %H:%M:%S"));
-        return Ok(());
-    }
-
+fn default_uptime() -> UResult<()> {
     print_time();
     print_uptime(None)?;
     print_nusers(None);
@@ -251,7 +233,7 @@ fn print_loadavg() {
 
 #[cfg(unix)]
 #[cfg(not(target_os = "openbsd"))]
-fn process_utmpx(file: Option<&std::ffi::OsString>) -> (Option<time_t>, usize) {
+fn process_utmpx(file: Option<&OsString>) -> (Option<time_t>, usize) {
     let mut nusers = 0;
     let mut boot_time = None;
 
diff --git a/tests/by-util/test_uptime.rs b/tests/by-util/test_uptime.rs
index 1fd65f9d6..7ec71ceba 100644
--- a/tests/by-util/test_uptime.rs
+++ b/tests/by-util/test_uptime.rs
@@ -251,7 +251,7 @@ fn test_uptime_with_extra_argument() {
         .arg("a")
         .arg("b")
         .fails()
-        .stderr_contains("extra operand 'b'");
+        .stderr_contains("unexpected value 'b'");
 }
 /// Checks whether uptime displays the correct stderr msg when its called with a directory
 #[test]