diff --git a/common/src/os.rs b/common/src/os.rs
index d04d2b807..40f403971 100644
--- a/common/src/os.rs
+++ b/common/src/os.rs
@@ -1,6 +1,6 @@
 // TODO: we can move more os-specific bindings/interfaces from stdlib::{os, posix, nt} to here
 
-use std::io;
+use std::{io, str::Utf8Error};
 
 #[cfg(windows)]
 pub fn errno() -> io::Error {
@@ -21,3 +21,14 @@ pub fn errno() -> io::Error {
 pub fn errno() -> io::Error {
     io::Error::last_os_error()
 }
+
+#[cfg(unix)]
+pub fn bytes_as_osstr(b: &[u8]) -> Result<&std::ffi::OsStr, Utf8Error> {
+    use std::os::unix::ffi::OsStrExt;
+    Ok(std::ffi::OsStr::from_bytes(b))
+}
+
+#[cfg(not(unix))]
+pub fn bytes_as_osstr(b: &[u8]) -> Result<&std::ffi::OsStr, Utf8Error> {
+    Ok(std::str::from_utf8(b)?.as_ref())
+}
diff --git a/vm/src/stdlib/os.rs b/vm/src/stdlib/os.rs
index 6140ea408..c0c8af32d 100644
--- a/vm/src/stdlib/os.rs
+++ b/vm/src/stdlib/os.rs
@@ -378,13 +378,8 @@ pub(super) struct FollowSymlinks(
     #[pyarg(named, name = "follow_symlinks", default = "true")] pub bool,
 );
 
-#[cfg(unix)]
-use platform::bytes_as_osstr;
-
-#[cfg(not(unix))]
 fn bytes_as_osstr<'a>(b: &'a [u8], vm: &VirtualMachine) -> PyResult<&'a ffi::OsStr> {
-    std::str::from_utf8(b)
-        .map(|s| s.as_ref())
+    rustpython_common::os::bytes_as_osstr(b)
         .map_err(|_| vm.new_unicode_decode_error("can't decode path for utf-8".to_owned()))
 }
 
diff --git a/vm/src/stdlib/posix.rs b/vm/src/stdlib/posix.rs
index 49d1fedda..52cb3402a 100644
--- a/vm/src/stdlib/posix.rs
+++ b/vm/src/stdlib/posix.rs
@@ -1,4 +1,4 @@
-use crate::{PyObjectRef, PyResult, VirtualMachine};
+use crate::{PyObjectRef, VirtualMachine};
 use std::os::unix::io::RawFd;
 
 pub fn raw_set_inheritable(fd: RawFd, inheritable: bool) -> nix::Result<()> {
@@ -12,14 +12,6 @@ pub fn raw_set_inheritable(fd: RawFd, inheritable: bool) -> nix::Result<()> {
     Ok(())
 }
 
-pub(super) fn bytes_as_osstr<'a>(
-    b: &'a [u8],
-    _vm: &VirtualMachine,
-) -> PyResult<&'a std::ffi::OsStr> {
-    use std::os::unix::ffi::OsStrExt;
-    Ok(std::ffi::OsStr::from_bytes(b))
-}
-
 pub(crate) fn make_module(vm: &VirtualMachine) -> PyObjectRef {
     let module = module::make_module(vm);
     super::os::extend_module(vm, &module);