diff --git a/src/libserialize/collection_impls.rs b/src/libserialize/collection_impls.rs
index d8ae9729224..de7eebe7bf3 100644
--- a/src/libserialize/collection_impls.rs
+++ b/src/libserialize/collection_impls.rs
@@ -15,6 +15,7 @@ use std::hash::{Hash, BuildHasher};
 use {Decodable, Encodable, Decoder, Encoder};
 use std::collections::{LinkedList, VecDeque, BTreeMap, BTreeSet, HashMap, HashSet};
 use std::rc::Rc;
+use std::sync::Arc;
 
 impl<
     T: Encodable
@@ -218,3 +219,26 @@ impl<T: Decodable> Decodable for Rc<[T]> {
         })
     }
 }
+
+impl<T: Encodable> Encodable for Arc<[T]> {
+    fn encode<E: Encoder>(&self, s: &mut E) -> Result<(), E::Error> {
+        s.emit_seq(self.len(), |s| {
+            for (index, e) in self.iter().enumerate() {
+                s.emit_seq_elt(index, |s| e.encode(s))?;
+            }
+            Ok(())
+        })
+    }
+}
+
+impl<T: Decodable> Decodable for Arc<[T]> {
+    fn decode<D: Decoder>(d: &mut D) -> Result<Arc<[T]>, D::Error> {
+        d.read_seq(|d, len| {
+            let mut vec = Vec::with_capacity(len);
+            for index in 0..len {
+                vec.push(d.read_seq_elt(index, |d| Decodable::decode(d))?);
+            }
+            Ok(vec.into())
+        })
+    }
+}
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