diff --git a/src/libstd/ffi/c_str.rs b/src/libstd/ffi/c_str.rs
index 5f0b11a616e..5dd7bb1c0c1 100644
--- a/src/libstd/ffi/c_str.rs
+++ b/src/libstd/ffi/c_str.rs
@@ -462,7 +462,7 @@ impl CString {
     /// assert_eq!(c_str, CStr::from_bytes_with_nul(b"foo\0").unwrap());
     /// ```
     #[inline]
-    #[unstable(feature = "as_c_str", issue = "40380")]
+    #[stable(feature = "as_c_str", since = "1.20.0")]
     pub fn as_c_str(&self) -> &CStr {
         &*self
     }
@@ -482,7 +482,7 @@ impl CString {
     /// let boxed = c_string.into_boxed_c_str();
     /// assert_eq!(&*boxed, CStr::from_bytes_with_nul(b"foo\0").unwrap());
     /// ```
-    #[unstable(feature = "into_boxed_c_str", issue = "40380")]
+    #[stable(feature = "into_boxed_c_str", since = "1.20.0")]
     pub fn into_boxed_c_str(self) -> Box<CStr> {
         unsafe { mem::transmute(self.into_inner()) }
     }
@@ -1009,7 +1009,7 @@ impl CStr {
     /// let boxed = c_string.into_boxed_c_str();
     /// assert_eq!(boxed.into_c_string(), CString::new("foo").unwrap());
     /// ```
-    #[unstable(feature = "into_boxed_c_str", issue = "40380")]
+    #[stable(feature = "into_boxed_c_str", since = "1.20.0")]
     pub fn into_c_string(self: Box<CStr>) -> CString {
         unsafe { mem::transmute(self) }
     }
diff --git a/src/libstd/ffi/os_str.rs b/src/libstd/ffi/os_str.rs
index 02a13ed7a5a..6f147ea0eec 100644
--- a/src/libstd/ffi/os_str.rs
+++ b/src/libstd/ffi/os_str.rs
@@ -260,7 +260,7 @@ impl OsString {
     ///
     /// let b: Box<OsStr> = s.into_boxed_os_str();
     /// ```
-    #[unstable(feature = "into_boxed_os_str", issue = "40380")]
+    #[stable(feature = "into_boxed_os_str", since = "1.20.0")]
     pub fn into_boxed_os_str(self) -> Box<OsStr> {
         unsafe { mem::transmute(self.inner.into_box()) }
     }
@@ -511,7 +511,7 @@ impl OsStr {
     ///
     /// [`Box`]: ../boxed/struct.Box.html
     /// [`OsString`]: struct.OsString.html
-    #[unstable(feature = "into_boxed_os_str", issue = "40380")]
+    #[stable(feature = "into_boxed_os_str", since = "1.20.0")]
     pub fn into_os_string(self: Box<OsStr>) -> OsString {
         let inner: Box<Slice> = unsafe { mem::transmute(self) };
         OsString { inner: Buf::from_box(inner) }
diff --git a/src/libstd/path.rs b/src/libstd/path.rs
index 619d0795421..e083ab0ef97 100644
--- a/src/libstd/path.rs
+++ b/src/libstd/path.rs
@@ -1327,7 +1327,7 @@ impl PathBuf {
     ///
     /// [`Box`]: ../../std/boxed/struct.Box.html
     /// [`Path`]: struct.Path.html
-    #[unstable(feature = "into_boxed_path", issue = "40380")]
+    #[stable(feature = "into_boxed_path", since = "1.20.0")]
     pub fn into_boxed_path(self) -> Box<Path> {
         unsafe { mem::transmute(self.inner.into_boxed_os_str()) }
     }
@@ -2300,7 +2300,7 @@ impl Path {
     ///
     /// [`Box`]: ../../std/boxed/struct.Box.html
     /// [`PathBuf`]: struct.PathBuf.html
-    #[unstable(feature = "into_boxed_path", issue = "40380")]
+    #[stable(feature = "into_boxed_path", since = "1.20.0")]
     pub fn into_path_buf(self: Box<Path>) -> PathBuf {
         let inner: Box<OsStr> = unsafe { mem::transmute(self) };
         PathBuf { inner: OsString::from(inner) }