diff --git a/Cargo.lock b/Cargo.lock
index ed6d2ebd6..8d2d1081b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -749,6 +749,16 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e88a8acf291dafb59c2d96e8f59828f3838bb1a70398823ade51a84de6a6deed"
 
+[[package]]
+name = "filepath"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0dd50318458226958db06f173610f54f01d26f0a9ccfa3d38bd60f70bc9939ff"
+dependencies = [
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "fixedbitset"
 version = "0.2.0"
@@ -1986,6 +1996,7 @@ dependencies = [
  "digest",
  "dns-lookup",
  "exitcode",
+ "filepath",
  "flame",
  "flamer",
  "flate2",
diff --git a/vm/Cargo.toml b/vm/Cargo.toml
index 66472be5d..0ac133af5 100644
--- a/vm/Cargo.toml
+++ b/vm/Cargo.toml
@@ -149,5 +149,8 @@ features = [
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 wasm-bindgen = "0.2"
 
+[target.'cfg(any(target_os = "linux", target_os = "macos", windows))'.dependencies]
+filepath = "0.1.1"
+
 [build-dependencies]
 itertools = "0.9"
diff --git a/vm/src/stdlib/os.rs b/vm/src/stdlib/os.rs
index 6257916b4..ac2910588 100644
--- a/vm/src/stdlib/os.rs
+++ b/vm/src/stdlib/os.rs
@@ -7,6 +7,8 @@ use std::time::{Duration, SystemTime};
 use std::{env, fs};
 
 use crossbeam_utils::atomic::AtomicCell;
+#[cfg(any(target_os = "linux", target_os = "macos", windows))]
+use filepath::FilePath;
 use num_bigint::BigInt;
 
 use super::errno::errors;
@@ -161,11 +163,25 @@ fn make_path<'a>(
     vm: &VirtualMachine,
     path: &'a PyPathLike,
     dir_fd: &DirFd,
-) -> PyResult<&'a ffi::OsStr> {
-    if dir_fd.0.is_some() {
-        Err(vm.new_os_error("dir_fd not supported yet".to_owned()))
-    } else {
-        Ok(path.path.as_os_str())
+) -> PyResult<std::borrow::Cow<'a, ffi::OsStr>> {
+    let path = &path.path;
+    if dir_fd.0.is_none() || path.is_absolute() {
+        return Ok(path.as_os_str().into());
+    }
+
+    cfg_if::cfg_if! {
+        if #[cfg(any(target_os = "linux", target_os = "macos", windows))] {
+            let dir_path = match rust_file(dir_fd.0.unwrap().into()).path() {
+                Ok(dir_path) => dir_path,
+                Err(_) => {
+                    return Err(vm.new_os_error(format!("Cannot determine path of dir_fd: {:?}", dir_fd.0)));
+                }
+            };
+            let p: PathBuf = vec![dir_path, path.to_path_buf()].iter().collect();
+            Ok(p.into_os_string().into())
+        } else {
+            return Err(vm.new_os_error("dir_fd not supported on wasi yet".to_owned()));
+        }
     }
 }
 
@@ -349,7 +365,7 @@ mod _os {
         vm: &VirtualMachine,
     ) -> PyResult<i64> {
         let fname = make_path(vm, &name, &dir_fd)?;
-        if osstr_contains_nul(fname) {
+        if osstr_contains_nul(&fname) {
             return Err(vm.new_value_error("embedded null character".to_owned()));
         }
 
@@ -504,14 +520,14 @@ mod _os {
     fn remove(path: PyPathLike, dir_fd: DirFd, vm: &VirtualMachine) -> PyResult<()> {
         let path = make_path(vm, &path, &dir_fd)?;
         let is_junction = cfg!(windows)
-            && fs::symlink_metadata(path).map_or(false, |meta| {
+            && fs::symlink_metadata(&path).map_or(false, |meta| {
                 let ty = meta.file_type();
                 ty.is_dir() && ty.is_symlink()
             });
         let res = if is_junction {
-            fs::remove_dir(path)
+            fs::remove_dir(&path)
         } else {
-            fs::remove_file(path)
+            fs::remove_file(&path)
         };
         res.map_err(|err| err.into_pyexception(vm))
     }
@@ -1221,7 +1237,7 @@ mod _os {
     pub(super) fn support_funcs(vm: &VirtualMachine) -> Vec<SupportFunc> {
         let mut supports = super::platform::support_funcs(vm);
         supports.extend(vec![
-            SupportFunc::new(vm, "open", open, None, Some(false), None),
+            SupportFunc::new(vm, "open", open, None, Some(true), None),
             SupportFunc::new(
                 vm,
                 "access",
@@ -1800,10 +1816,10 @@ mod posix {
         let path = make_path(vm, &path, &dir_fd)?;
         let body = move || {
             use std::os::unix::fs::PermissionsExt;
-            let meta = fs_metadata(path, follow_symlinks.0)?;
+            let meta = fs_metadata(&path, follow_symlinks.0)?;
             let mut permissions = meta.permissions();
             permissions.set_mode(mode);
-            fs::set_permissions(path, permissions)
+            fs::set_permissions(&path, permissions)
         };
         body().map_err(|err| err.into_pyexception(vm))
     }
@@ -2675,14 +2691,14 @@ mod nt {
         const S_IWRITE: u32 = 128;
         let path = make_path(vm, &path, &dir_fd)?;
         let metadata = if follow_symlinks.0 {
-            fs::metadata(path)
+            fs::metadata(&path)
         } else {
-            fs::symlink_metadata(path)
+            fs::symlink_metadata(&path)
         };
         let meta = metadata.map_err(|err| err.into_pyexception(vm))?;
         let mut permissions = meta.permissions();
         permissions.set_readonly(mode & S_IWRITE != 0);
-        fs::set_permissions(path, permissions).map_err(|err| err.into_pyexception(vm))
+        fs::set_permissions(&path, permissions).map_err(|err| err.into_pyexception(vm))
     }
 
     // cwait is available on MSVC only (according to CPython)