diff --git a/src/libstd/ffi/os_str.rs b/src/libstd/ffi/os_str.rs
index 01e7a57cd003f..13aee783750f1 100644
--- a/src/libstd/ffi/os_str.rs
+++ b/src/libstd/ffi/os_str.rs
@@ -960,6 +960,7 @@ impl IntoInner<Buf> for OsString {
 }
 
 impl AsInner<Slice> for OsStr {
+    #[inline]
     fn as_inner(&self) -> &Slice {
         &self.inner
     }
diff --git a/src/libstd/sys_common/os_str_bytes.rs b/src/libstd/sys_common/os_str_bytes.rs
index 7cc93477a73c7..a4961974d89ab 100644
--- a/src/libstd/sys_common/os_str_bytes.rs
+++ b/src/libstd/sys_common/os_str_bytes.rs
@@ -236,9 +236,11 @@ pub trait OsStrExt {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl OsStrExt for OsStr {
+    #[inline]
     fn from_bytes(slice: &[u8]) -> &OsStr {
         unsafe { mem::transmute(slice) }
     }
+    #[inline]
     fn as_bytes(&self) -> &[u8] {
         &self.as_inner().inner
     }