diff --git a/src/libcore/hash/mod.rs b/src/libcore/hash/mod.rs
index a660cf0cf2d..234252faa6e 100644
--- a/src/libcore/hash/mod.rs
+++ b/src/libcore/hash/mod.rs
@@ -89,8 +89,7 @@ pub trait Hash {
     fn hash<H: Hasher>(&self, state: &mut H);
 
     /// Feeds a slice of this type into the state provided.
-    #[unstable(feature = "hash_slice",
-               reason = "module was recently redesigned")]
+    #[stable(feature = "hash_slice", since = "1.3.0")]
     fn hash_slice<H: Hasher>(data: &[Self], state: &mut H) where Self: Sized {
         for piece in data {
             piece.hash(state);
@@ -111,29 +110,29 @@ pub trait Hasher {
 
     /// Write a single `u8` into this hasher
     #[inline]
-    #[unstable(feature = "hasher_write", reason = "module was recently redesigned")]
+    #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_u8(&mut self, i: u8) { self.write(&[i]) }
     /// Write a single `u16` into this hasher.
     #[inline]
-    #[unstable(feature = "hasher_write", reason = "module was recently redesigned")]
+    #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_u16(&mut self, i: u16) {
         self.write(&unsafe { mem::transmute::<_, [u8; 2]>(i) })
     }
     /// Write a single `u32` into this hasher.
     #[inline]
-    #[unstable(feature = "hasher_write", reason = "module was recently redesigned")]
+    #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_u32(&mut self, i: u32) {
         self.write(&unsafe { mem::transmute::<_, [u8; 4]>(i) })
     }
     /// Write a single `u64` into this hasher.
     #[inline]
-    #[unstable(feature = "hasher_write", reason = "module was recently redesigned")]
+    #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_u64(&mut self, i: u64) {
         self.write(&unsafe { mem::transmute::<_, [u8; 8]>(i) })
     }
     /// Write a single `usize` into this hasher.
     #[inline]
-    #[unstable(feature = "hasher_write", reason = "module was recently redesigned")]
+    #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_usize(&mut self, i: usize) {
         if cfg!(target_pointer_width = "32") {
             self.write_u32(i as u32)
@@ -144,23 +143,23 @@ pub trait Hasher {
 
     /// Write a single `i8` into this hasher.
     #[inline]
-    #[unstable(feature = "hasher_write", reason = "module was recently redesigned")]
+    #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_i8(&mut self, i: i8) { self.write_u8(i as u8) }
     /// Write a single `i16` into this hasher.
     #[inline]
-    #[unstable(feature = "hasher_write", reason = "module was recently redesigned")]
+    #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_i16(&mut self, i: i16) { self.write_u16(i as u16) }
     /// Write a single `i32` into this hasher.
     #[inline]
-    #[unstable(feature = "hasher_write", reason = "module was recently redesigned")]
+    #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_i32(&mut self, i: i32) { self.write_u32(i as u32) }
     /// Write a single `i64` into this hasher.
     #[inline]
-    #[unstable(feature = "hasher_write", reason = "module was recently redesigned")]
+    #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_i64(&mut self, i: i64) { self.write_u64(i as u64) }
     /// Write a single `isize` into this hasher.
     #[inline]
-    #[unstable(feature = "hasher_write", reason = "module was recently redesigned")]
+    #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_isize(&mut self, i: isize) { self.write_usize(i as usize) }
 }
 
diff --git a/src/libstd/error.rs b/src/libstd/error.rs
index b21b2edf2ec..4d08f08bb6e 100644
--- a/src/libstd/error.rs
+++ b/src/libstd/error.rs
@@ -168,7 +168,7 @@ impl Error for string::FromUtf16Error {
 // copied from any.rs
 impl Error + 'static {
     /// Returns true if the boxed type is the same as `T`
-    #[unstable(feature = "error_downcast", reason = "recently added")]
+    #[stable(feature = "error_downcast", since = "1.3.0")]
     #[inline]
     pub fn is<T: Error + 'static>(&self) -> bool {
         // Get TypeId of the type this function is instantiated with
@@ -183,7 +183,7 @@ impl Error + 'static {
 
     /// Returns some reference to the boxed value if it is of type `T`, or
     /// `None` if it isn't.
-    #[unstable(feature = "error_downcast", reason = "recently added")]
+    #[stable(feature = "error_downcast", since = "1.3.0")]
     #[inline]
     pub fn downcast_ref<T: Error + 'static>(&self) -> Option<&T> {
         if self.is::<T>() {
@@ -201,7 +201,7 @@ impl Error + 'static {
 
     /// Returns some mutable reference to the boxed value if it is of type `T`, or
     /// `None` if it isn't.
-    #[unstable(feature = "error_downcast", reason = "recently added")]
+    #[stable(feature = "error_downcast", since = "1.3.0")]
     #[inline]
     pub fn downcast_mut<T: Error + 'static>(&mut self) -> Option<&mut T> {
         if self.is::<T>() {
@@ -220,21 +220,44 @@ impl Error + 'static {
 
 impl Error + 'static + Send {
     /// Forwards to the method defined on the type `Any`.
-    #[unstable(feature = "error_downcast", reason = "recently added")]
+    #[stable(feature = "error_downcast", since = "1.3.0")]
     #[inline]
     pub fn is<T: Error + 'static>(&self) -> bool {
         <Error + 'static>::is::<T>(self)
     }
 
     /// Forwards to the method defined on the type `Any`.
-    #[unstable(feature = "error_downcast", reason = "recently added")]
+    #[stable(feature = "error_downcast", since = "1.3.0")]
     #[inline]
     pub fn downcast_ref<T: Error + 'static>(&self) -> Option<&T> {
         <Error + 'static>::downcast_ref::<T>(self)
     }
 
     /// Forwards to the method defined on the type `Any`.
-    #[unstable(feature = "error_downcast", reason = "recently added")]
+    #[stable(feature = "error_downcast", since = "1.3.0")]
+    #[inline]
+    pub fn downcast_mut<T: Error + 'static>(&mut self) -> Option<&mut T> {
+        <Error + 'static>::downcast_mut::<T>(self)
+    }
+}
+
+impl Error + 'static + Send + Sync {
+    /// Forwards to the method defined on the type `Any`.
+    #[stable(feature = "error_downcast", since = "1.3.0")]
+    #[inline]
+    pub fn is<T: Error + 'static>(&self) -> bool {
+        <Error + 'static>::is::<T>(self)
+    }
+
+    /// Forwards to the method defined on the type `Any`.
+    #[stable(feature = "error_downcast", since = "1.3.0")]
+    #[inline]
+    pub fn downcast_ref<T: Error + 'static>(&self) -> Option<&T> {
+        <Error + 'static>::downcast_ref::<T>(self)
+    }
+
+    /// Forwards to the method defined on the type `Any`.
+    #[stable(feature = "error_downcast", since = "1.3.0")]
     #[inline]
     pub fn downcast_mut<T: Error + 'static>(&mut self) -> Option<&mut T> {
         <Error + 'static>::downcast_mut::<T>(self)
@@ -243,7 +266,7 @@ impl Error + 'static + Send {
 
 impl Error {
     #[inline]
-    #[unstable(feature = "error_downcast", reason = "recently added")]
+    #[stable(feature = "error_downcast", since = "1.3.0")]
     /// Attempt to downcast the box to a concrete type.
     pub fn downcast<T: Error + 'static>(self: Box<Self>) -> Result<Box<T>, Box<Error>> {
         if self.is::<T>() {
@@ -264,9 +287,10 @@ impl Error {
 
 impl Error + Send {
     #[inline]
-    #[unstable(feature = "error_downcast", reason = "recently added")]
+    #[stable(feature = "error_downcast", since = "1.3.0")]
     /// Attempt to downcast the box to a concrete type.
-    pub fn downcast<T: Error + 'static>(self: Box<Self>) -> Result<Box<T>, Box<Error + Send>> {
+    pub fn downcast<T: Error + 'static>(self: Box<Self>)
+                                        -> Result<Box<T>, Box<Error + Send>> {
         let err: Box<Error> = self;
         <Error>::downcast(err).map_err(|s| unsafe {
             // reapply the Send marker
@@ -274,3 +298,63 @@ impl Error + Send {
         })
     }
 }
+
+impl Error + Send + Sync {
+    #[inline]
+    #[stable(feature = "error_downcast", since = "1.3.0")]
+    /// Attempt to downcast the box to a concrete type.
+    pub fn downcast<T: Error + 'static>(self: Box<Self>)
+                                        -> Result<Box<T>, Box<Self>> {
+        let err: Box<Error> = self;
+        <Error>::downcast(err).map_err(|s| unsafe {
+            // reapply the Send+Sync marker
+            transmute::<Box<Error>, Box<Error + Send + Sync>>(s)
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use prelude::v1::*;
+    use super::Error;
+    use fmt;
+
+    #[derive(Debug, PartialEq)]
+    struct A;
+    #[derive(Debug, PartialEq)]
+    struct B;
+
+    impl fmt::Display for A {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            write!(f, "A")
+        }
+    }
+    impl fmt::Display for B {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            write!(f, "B")
+        }
+    }
+
+    impl Error for A {
+        fn description(&self) -> &str { "A-desc" }
+    }
+    impl Error for B {
+        fn description(&self) -> &str { "A-desc" }
+    }
+
+    #[test]
+    fn downcasting() {
+        let mut a = A;
+        let mut a = &mut a as &mut (Error + 'static);
+        assert_eq!(a.downcast_ref::<A>(), Some(&A));
+        assert_eq!(a.downcast_ref::<B>(), None);
+        assert_eq!(a.downcast_mut::<A>(), Some(&mut A));
+        assert_eq!(a.downcast_mut::<B>(), None);
+
+        let a: Box<Error> = Box::new(A);
+        match a.downcast::<B>() {
+            Ok(..) => panic!("expected error"),
+            Err(e) => assert_eq!(*e.downcast::<A>().unwrap(), A),
+        }
+    }
+}
diff --git a/src/libstd/io/error.rs b/src/libstd/io/error.rs
index 3b48ff30960..e12e202148b 100644
--- a/src/libstd/io/error.rs
+++ b/src/libstd/io/error.rs
@@ -219,8 +219,7 @@ impl Error {
     ///
     /// If this `Error` was constructed via `new` then this function will
     /// return `Some`, otherwise it will return `None`.
-    #[unstable(feature = "io_error_inner",
-               reason = "recently added and requires UFCS to downcast")]
+    #[stable(feature = "io_error_inner", since = "1.3.0")]
     pub fn get_ref(&self) -> Option<&(error::Error+Send+Sync+'static)> {
         match self.repr {
             Repr::Os(..) => None,
@@ -233,8 +232,7 @@ impl Error {
     ///
     /// If this `Error` was constructed via `new` then this function will
     /// return `Some`, otherwise it will return `None`.
-    #[unstable(feature = "io_error_inner",
-               reason = "recently added and requires UFCS to downcast")]
+    #[stable(feature = "io_error_inner", since = "1.3.0")]
     pub fn get_mut(&mut self) -> Option<&mut (error::Error+Send+Sync+'static)> {
         match self.repr {
             Repr::Os(..) => None,
@@ -246,8 +244,7 @@ impl Error {
     ///
     /// If this `Error` was constructed via `new` then this function will
     /// return `Some`, otherwise it will return `None`.
-    #[unstable(feature = "io_error_inner",
-               reason = "recently added and requires UFCS to downcast")]
+    #[stable(feature = "io_error_inner", since = "1.3.0")]
     pub fn into_inner(self) -> Option<Box<error::Error+Send+Sync>> {
         match self.repr {
             Repr::Os(..) => None,
@@ -349,10 +346,10 @@ mod test {
         // we have to call all of these UFCS style right now since method
         // resolution won't implicitly drop the Send+Sync bounds
         let mut err = Error::new(ErrorKind::Other, TestError);
-        assert!(error::Error::is::<TestError>(err.get_ref().unwrap()));
+        assert!(err.get_ref().unwrap().is::<TestError>());
         assert_eq!("asdf", err.get_ref().unwrap().description());
-        assert!(error::Error::is::<TestError>(err.get_mut().unwrap()));
+        assert!(err.get_mut().unwrap().is::<TestError>());
         let extracted = err.into_inner().unwrap();
-        error::Error::downcast::<TestError>(extracted).unwrap();
+        extracted.downcast::<TestError>().unwrap();
     }
 }
diff --git a/src/libstd/process.rs b/src/libstd/process.rs
index 3471805b2bc..e07ed37125b 100644
--- a/src/libstd/process.rs
+++ b/src/libstd/process.rs
@@ -505,7 +505,7 @@ impl Child {
     }
 
     /// Returns the OS-assigned process identifier associated with this child.
-    #[unstable(feature = "process_id", reason = "api recently added")]
+    #[stable(feature = "process_id", since = "1.3.0")]
     pub fn id(&self) -> u32 {
         self.handle.id()
     }