diff --git a/serde/src/ser/impls.rs b/serde/src/ser/impls.rs
index 409ec470..3000a015 100644
--- a/serde/src/ser/impls.rs
+++ b/serde/src/ser/impls.rs
@@ -29,8 +29,6 @@ use std::rc::Rc;
 use alloc::rc::Rc;
 #[cfg(feature = "std")]
 use std::time::Duration;
-#[cfg(feature = "std")]
-use std;
 
 #[cfg(feature = "std")]
 use std::sync::Arc;
@@ -267,7 +265,7 @@ impl<T> Serialize for VecDeque<T>
 ///////////////////////////////////////////////////////////////////////////////
 
 #[cfg(feature = "std")]
-impl<Idx: Serialize> Serialize for std::ops::Range<Idx> {
+impl<Idx: Serialize> Serialize for ops::Range<Idx> {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer
     {
@@ -281,23 +279,6 @@ impl<Idx: Serialize> Serialize for std::ops::Range<Idx> {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-#[cfg(feature = "unstable")]
-impl<A> Serialize for ops::Range<A>
-    where ops::Range<A>: ExactSizeIterator + iter::Iterator<Item = A> + Clone,
-          A: Serialize
-{
-    #[inline]
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-        where S: Serializer
-    {
-        let mut seq = try!(serializer.serialize_seq(Some(self.len())));
-        for e in self.clone() {
-            try!(seq.serialize_element(&e));
-        }
-        seq.end()
-    }
-}
-
 #[cfg(feature = "unstable")]
 impl<A> Serialize for ops::RangeInclusive<A>
     where ops::RangeInclusive<A>: ExactSizeIterator + iter::Iterator<Item = A> + Clone,