diff --git a/library/std/src/sys/os_str/bytes.rs b/library/std/src/sys/os_str/bytes.rs
index a57da01a5d85d..048e5def1369b 100644
--- a/library/std/src/sys/os_str/bytes.rs
+++ b/library/std/src/sys/os_str/bytes.rs
@@ -16,12 +16,12 @@ mod tests;
 
 #[derive(Hash)]
 #[repr(transparent)]
-pub struct Buf {
+pub(crate) struct Buf {
     pub inner: Vec<u8>,
 }
 
 #[repr(transparent)]
-pub struct Slice {
+pub(crate) struct Slice {
     pub inner: [u8],
 }
 
diff --git a/library/std/src/sys/os_str/mod.rs b/library/std/src/sys/os_str/mod.rs
index f7007cbf18b4c..dd37b558a096e 100644
--- a/library/std/src/sys/os_str/mod.rs
+++ b/library/std/src/sys/os_str/mod.rs
@@ -3,14 +3,14 @@
 cfg_select! {
     any(target_os = "windows", target_os = "uefi") => {
         mod wtf8;
-        pub use wtf8::{Buf, Slice};
+        pub(crate) use wtf8::{Buf, Slice};
     }
     any(target_os = "motor") => {
         mod utf8;
-        pub use utf8::{Buf, Slice};
+        pub(crate) use utf8::{Buf, Slice};
     }
     _ => {
         mod bytes;
-        pub use bytes::{Buf, Slice};
+        pub(crate) use bytes::{Buf, Slice};
     }
 }
diff --git a/library/std/src/sys/os_str/utf8.rs b/library/std/src/sys/os_str/utf8.rs
index 289f58aa480f7..3648962da5eeb 100644
--- a/library/std/src/sys/os_str/utf8.rs
+++ b/library/std/src/sys/os_str/utf8.rs
@@ -11,12 +11,12 @@ use crate::{fmt, mem};
 
 #[derive(Hash)]
 #[repr(transparent)]
-pub struct Buf {
+pub(crate) struct Buf {
     pub inner: String,
 }
 
 #[repr(transparent)]
-pub struct Slice {
+pub(crate) struct Slice {
     pub inner: str,
 }
 
diff --git a/library/std/src/sys/os_str/wtf8.rs b/library/std/src/sys/os_str/wtf8.rs
index 9a32ab3f3ea12..5f9d64dc5d09c 100644
--- a/library/std/src/sys/os_str/wtf8.rs
+++ b/library/std/src/sys/os_str/wtf8.rs
@@ -13,12 +13,12 @@ use crate::{fmt, mem};
 
 #[derive(Hash)]
 #[repr(transparent)]
-pub struct Buf {
+pub(crate) struct Buf {
     pub inner: Wtf8Buf,
 }
 
 #[repr(transparent)]
-pub struct Slice {
+pub(crate) struct Slice {
     pub inner: Wtf8,
 }