diff --git a/Cargo.lock b/Cargo.lock
index bce891473bd..d8adfd4f5a6 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1246,6 +1246,7 @@ dependencies = [
 name = "hashglobe"
 version = "0.1.0"
 dependencies = [
+ "heapsize 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
diff --git a/components/hashglobe/Cargo.toml b/components/hashglobe/Cargo.toml
index ce9513cdcf7..e92b7fc7794 100644
--- a/components/hashglobe/Cargo.toml
+++ b/components/hashglobe/Cargo.toml
@@ -11,6 +11,7 @@ readme = "README.md"
 
 [dependencies]
 libc = "0.2"
+heapsize = "0.4"
 
 [dev-dependencies]
 rand = "0.3"
\ No newline at end of file
diff --git a/components/hashglobe/src/fake.rs b/components/hashglobe/src/fake.rs
index 5b635226474..baf06ab0470 100644
--- a/components/hashglobe/src/fake.rs
+++ b/components/hashglobe/src/fake.rs
@@ -8,9 +8,14 @@ use std::hash::{BuildHasher, Hash};
 use std::collections::HashMap as StdMap;
 use std::collections::HashSet as StdSet;
 use std::ops::{Deref, DerefMut};
+use std::fmt;
 
-pub use std::collections::hash_map::{Entry, RandomState};
+use heapsize::HeapSizeOf;
 
+pub use std::collections::hash_map::{Entry, RandomState, Iter as MapIter, IterMut as MapIterMut};
+pub use std::collections::hash_set::{Iter as SetIter, IntoIter as SetIntoIter};
+
+#[derive(Clone)]
 pub struct HashMap<K, V, S = RandomState>(StdMap<K, V, S>);
 
 
@@ -86,6 +91,7 @@ impl<K, V, S> HashMap<K, V, S>
     }
 }
 
+#[derive(Clone)]
 pub struct HashSet<T, S = RandomState>(StdSet<T, S>);
 
 
@@ -147,3 +153,133 @@ impl<T, S> HashSet<T, S>
         Ok(self.insert(value))
     }
 }
+
+// Pass through trait impls
+// We can't derive these since the bounds are not obvious to the derive macro
+
+
+impl<K: HeapSizeOf + Hash + Eq, V: HeapSizeOf, S: BuildHasher> HeapSizeOf for HashMap<K, V, S> {
+    fn heap_size_of_children(&self) -> usize {
+        self.0.heap_size_of_children()
+    } 
+}
+
+impl<K: Hash + Eq, V, S: BuildHasher + Default> Default for HashMap<K, V, S> {
+    fn default() -> Self {
+        HashMap(Default::default())
+    }
+}
+
+impl<K, V, S> fmt::Debug for HashMap<K, V, S>
+    where K: Eq + Hash + fmt::Debug,
+          V: fmt::Debug,
+          S: BuildHasher {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl<K, V, S> PartialEq for HashMap<K, V, S>
+    where K: Eq + Hash,
+          V: PartialEq,
+          S: BuildHasher
+{
+    fn eq(&self, other: &HashMap<K, V, S>) -> bool {
+        self.0.eq(&other.0)
+    }
+}
+
+impl<K, V, S> Eq for HashMap<K, V, S>
+    where K: Eq + Hash,
+          V: Eq,
+          S: BuildHasher
+{
+}
+
+impl<'a, K, V, S> IntoIterator for &'a HashMap<K, V, S>
+    where K: Eq + Hash,
+          S: BuildHasher
+{
+    type Item = (&'a K, &'a V);
+    type IntoIter = MapIter<'a, K, V>;
+
+    fn into_iter(self) -> MapIter<'a, K, V> {
+        self.0.iter()
+    }
+}
+
+impl<'a, K, V, S> IntoIterator for &'a mut HashMap<K, V, S>
+    where K: Eq + Hash,
+          S: BuildHasher
+{
+    type Item = (&'a K, &'a mut V);
+    type IntoIter = MapIterMut<'a, K, V>;
+
+    fn into_iter(self) -> MapIterMut<'a, K, V> {
+        self.0.iter_mut()
+    }
+}
+
+
+impl<T: HeapSizeOf + Eq + Hash, S: BuildHasher> HeapSizeOf for HashSet<T, S> {
+    fn heap_size_of_children(&self) -> usize {
+        self.0.heap_size_of_children()
+    } 
+}
+
+impl<T: Eq + Hash, S: BuildHasher + Default> Default for HashSet<T, S> {
+    fn default() -> Self {
+        HashSet(Default::default())
+    }
+}
+
+impl<T, S> fmt::Debug for HashSet<T, S>
+    where T: Eq + Hash + fmt::Debug,
+          S: BuildHasher
+{
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl<T, S> PartialEq for HashSet<T, S>
+    where T: Eq + Hash,
+          S: BuildHasher
+{
+    fn eq(&self, other: &HashSet<T, S>) -> bool {
+        self.0.eq(&other.0)
+    }
+}
+
+impl<T, S> Eq for HashSet<T, S>
+    where T: Eq + Hash,
+          S: BuildHasher
+{
+}
+
+impl<'a, T, S> IntoIterator for &'a HashSet<T, S>
+    where T: Eq + Hash,
+          S: BuildHasher
+{
+    type Item = &'a T;
+    type IntoIter = SetIter<'a, T>;
+
+    fn into_iter(self) -> SetIter<'a, T> {
+        self.0.iter()
+    }
+}
+
+impl<T, S> IntoIterator for HashSet<T, S>
+    where T: Eq + Hash,
+          S: BuildHasher
+{
+    type Item = T;
+    type IntoIter = SetIntoIter<T>;
+
+
+    fn into_iter(self) -> SetIntoIter<T> {
+        self.0.into_iter()
+    }
+}
+
+
diff --git a/components/hashglobe/src/lib.rs b/components/hashglobe/src/lib.rs
index a29f5c1b001..4bd32e59e96 100644
--- a/components/hashglobe/src/lib.rs
+++ b/components/hashglobe/src/lib.rs
@@ -1,5 +1,7 @@
 pub use std::*;
 
+extern crate heapsize;
+
 mod table;
 mod shim;
 mod alloc;