diff --git a/library/std/src/ffi/os_str.rs b/library/std/src/ffi/os_str.rs
index e5c1e6a4fbc3ef35fee570747bf1712716a7724e..28aa10f57358b427c6acd504bd639ef6def0315f 100644
--- a/library/std/src/ffi/os_str.rs
+++ b/library/std/src/ffi/os_str.rs
@@ -834,6 +834,7 @@ pub fn to_os_string(&self) -> OsString {
     /// and [`std::ffi`] for platform-specific, specified conversions.
     ///
     /// [`std::ffi`]: crate::ffi
+    #[cfg(windows)]
     #[inline]
     #[stable(feature = "os_str_bytes", since = "1.71.0")]
     pub fn as_encoded_bytes(&self) -> &[u8] {