diff --git a/library/std/src/os/unix/ffi/os_str.rs b/library/std/src/os/unix/ffi/os_str.rs
index 54c9a9382f2..650f712bc6e 100644
--- a/library/std/src/os/unix/ffi/os_str.rs
+++ b/library/std/src/os/unix/ffi/os_str.rs
@@ -28,9 +28,11 @@ pub trait OsStringExt: Sealed {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl OsStringExt for OsString {
+    #[inline]
     fn from_vec(vec: Vec<u8>) -> OsString {
         FromInner::from_inner(Buf { inner: vec })
     }
+    #[inline]
     fn into_vec(self) -> Vec<u8> {
         self.into_inner().inner
     }