diff --git a/CHANGELOG.md b/CHANGELOG.md
index c2ba41e0586..449bb318854 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@ _gated behind `unstable-v4`_
 - Leading dashes in `Arg::long` are no longer allowed (#3691)
 - Verify `required` is not used with conditional required settings (#3660)
 - Disallow more `value_names` than `number_of_values` (#2695)
+- Don't correct argument id in `default_value_ifs_os`(#3815)
 - *(assert)* Always enforce that version is specified when the `ArgAction::Version` is used
 - *(assert)* Add missing `#[track_caller]`s to make it easier to debug asserts
 - *(help)* Use `Command::display_name` in the help title rather than `Command::bin_name`
diff --git a/tests/builder/arg_settings.rs b/tests/builder/arg_settings.rs
index 719721605ec..d4e900ab92c 100644
--- a/tests/builder/arg_settings.rs
+++ b/tests/builder/arg_settings.rs
@@ -1,7 +1,5 @@
 #![allow(deprecated)]
-
-use clap::{Arg, ArgSettings, Command};
-use std::ffi::OsStr;
+use clap::{Arg, ArgSettings};
 
 #[test]
 fn setting() {
@@ -44,42 +42,3 @@ fn unset_setting_bitor() {
     assert!(!m.is_hide_set(), "{:#?}", m);
     assert!(!m.is_last_set(), "{:#?}", m);
 }
-
-#[test]
-fn default_value_ifs_os() {
-    let cmd = Command::new("my_cargo")
-        .arg(
-            Arg::new("flag")
-                .long("flag")
-                .allow_invalid_utf8(true)
-                .takes_value(true),
-        )
-        .arg(
-            Arg::new("other")
-                .long("other")
-                .allow_invalid_utf8(true)
-                .default_value_ifs_os(&[(
-                    "flag",
-                    Some("标记2").map(OsStr::new),
-                    Some("flag=标记2").map(OsStr::new),
-                )]),
-        );
-    let result = cmd.try_get_matches_from([
-        OsStr::new("my_cargo"),
-        OsStr::new("--flag"),
-        OsStr::new("标记2"),
-    ]);
-    assert!(result.is_ok());
-    match result {
-        Ok(arg_matches) => {
-            assert_eq!(arg_matches.value_of_os("flag"), Some(OsStr::new("标记2")));
-            assert_eq!(
-                arg_matches.value_of_os("other"),
-                Some(OsStr::new("flag=标记2")),
-            );
-        }
-        Err(e) => {
-            println!("{}", e.to_string());
-        }
-    }
-}
diff --git a/tests/builder/default_vals.rs b/tests/builder/default_vals.rs
index ec83f7013a5..dbe18a1d21d 100644
--- a/tests/builder/default_vals.rs
+++ b/tests/builder/default_vals.rs
@@ -1,5 +1,8 @@
+use std::ffi::OsStr;
+use std::ffi::OsString;
+
 use super::utils;
-use clap::{arg, error::ErrorKind, Arg, Command};
+use clap::{arg, error::ErrorKind, value_parser, Arg, Command};
 
 #[test]
 fn opts() {
@@ -596,6 +599,38 @@ fn default_ifs_arg_present_order() {
     );
 }
 
+#[test]
+fn default_value_ifs_os() {
+    let cmd = Command::new("my_cargo")
+        .arg(
+            Arg::new("flag")
+                .long("flag")
+                .value_parser(value_parser!(OsString))
+                .takes_value(true),
+        )
+        .arg(
+            Arg::new("other")
+                .long("other")
+                .value_parser(value_parser!(OsString))
+                .default_value_ifs_os(&[(
+                    "flag",
+                    Some(OsStr::new("标记2")),
+                    Some(OsStr::new("flag=标记2")),
+                )]),
+        );
+    let result = cmd.try_get_matches_from(["my_cargo", "--flag", "标记2"]);
+    assert!(result.is_ok(), "{}", result.unwrap_err());
+    let m = result.unwrap();
+    assert_eq!(
+        m.get_one::<OsString>("flag").map(OsString::as_os_str),
+        Some(OsStr::new("标记2"))
+    );
+    assert_eq!(
+        m.get_one::<OsString>("other").map(OsString::as_os_str),
+        Some(OsStr::new("flag=标记2")),
+    );
+}
+
 // Interaction with requires
 
 #[test]