diff --git a/src/branch.rs b/src/branch.rs
index 8197415d1b..681f1c5327 100644
--- a/src/branch.rs
+++ b/src/branch.rs
@@ -113,7 +113,8 @@ impl<'repo> Branches<'repo> {
     }
 }
 
-impl<'repo> Iterator<(Branch<'repo>, BranchType)> for Branches<'repo> {
+impl<'repo> Iterator for Branches<'repo> {
+    type Item = (Branch<'repo>, BranchType);
     fn next(&mut self) -> Option<(Branch<'repo>, BranchType)> {
         let mut ret = 0 as *mut raw::git_reference;
         let mut typ = raw::GIT_BRANCH_LOCAL;
diff --git a/src/commit.rs b/src/commit.rs
index 32bdaeddf6..804acda999 100644
--- a/src/commit.rs
+++ b/src/commit.rs
@@ -246,35 +246,37 @@ impl<'repo> Commit<'repo> {
     }
 }
 
-impl<'repo, 'commit> Iterator<Commit<'repo>> for Parents<'commit, 'repo> {
+impl<'repo, 'commit> Iterator for Parents<'commit, 'repo> {
+    type Item = Commit<'repo>;
     fn next(&mut self) -> Option<Commit<'repo>> {
         self.range.next().map(|i| self.commit.parent(i).unwrap())
     }
     fn size_hint(&self) -> (uint, Option<uint>) { self.range.size_hint() }
 }
 
-impl<'repo, 'commit> DoubleEndedIterator<Commit<'repo>> for Parents<'commit, 'repo> {
+impl<'repo, 'commit> DoubleEndedIterator for Parents<'commit, 'repo> {
     fn next_back(&mut self) -> Option<Commit<'repo>> {
         self.range.next_back().map(|i| self.commit.parent(i).unwrap())
     }
 }
 
-impl<'repo, 'commit> ExactSizeIterator<Commit<'repo>> for Parents<'commit, 'repo> {}
+impl<'repo, 'commit> ExactSizeIterator for Parents<'commit, 'repo> {}
 
-impl<'commit> Iterator<Oid> for ParentIds<'commit> {
+impl<'commit> Iterator for ParentIds<'commit> {
+    type Item = Oid;
     fn next(&mut self) -> Option<Oid> {
         self.range.next().map(|i| self.commit.parent_id(i).unwrap())
     }
     fn size_hint(&self) -> (uint, Option<uint>) { self.range.size_hint() }
 }
 
-impl<'commit> DoubleEndedIterator<Oid> for ParentIds<'commit> {
+impl<'commit> DoubleEndedIterator for ParentIds<'commit> {
     fn next_back(&mut self) -> Option<Oid> {
         self.range.next_back().map(|i| self.commit.parent_id(i).unwrap())
     }
 }
 
-impl<'commit> ExactSizeIterator<Oid> for ParentIds<'commit> {}
+impl<'commit> ExactSizeIterator for ParentIds<'commit> {}
 
 #[unsafe_destructor]
 impl<'repo> Drop for Commit<'repo> {
diff --git a/src/config.rs b/src/config.rs
index c4460b1a9e..2dac25b8eb 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -386,7 +386,8 @@ impl<'cfg> ConfigEntries<'cfg> {
 //
 // It's also not implemented for `&'b mut T` so we can have multiple entries
 // (ok).
-impl<'cfg, 'b> Iterator<ConfigEntry<'b>> for &'b ConfigEntries<'cfg> {
+impl<'cfg, 'b> Iterator for &'b ConfigEntries<'cfg> {
+    type Item = ConfigEntry<'b>;
     fn next(&mut self) -> Option<ConfigEntry<'b>> {
         let mut raw = 0 as *mut raw::git_config_entry;
         unsafe {
diff --git a/src/diff.rs b/src/diff.rs
index dcedd501c9..f1688c9f5d 100644
--- a/src/diff.rs
+++ b/src/diff.rs
@@ -647,18 +647,19 @@ impl DiffOptions {
     // TODO: expose ignore_submodules, notify_cb/notify_payload
 }
 
-impl<'diff> Iterator<DiffDelta<'diff>> for Deltas<'diff> {
+impl<'diff> Iterator for Deltas<'diff> {
+    type Item = DiffDelta<'diff>;
     fn next(&mut self) -> Option<DiffDelta<'diff>> {
         self.range.next().and_then(|i| self.diff.get_delta(i))
     }
     fn size_hint(&self) -> (uint, Option<uint>) { self.range.size_hint() }
 }
-impl<'diff> DoubleEndedIterator<DiffDelta<'diff>> for Deltas<'diff> {
+impl<'diff> DoubleEndedIterator for Deltas<'diff> {
     fn next_back(&mut self) -> Option<DiffDelta<'diff>> {
         self.range.next_back().and_then(|i| self.diff.get_delta(i))
     }
 }
-impl<'diff> ExactSizeIterator<DiffDelta<'diff>> for Deltas<'diff> {}
+impl<'diff> ExactSizeIterator for Deltas<'diff> {}
 
 impl<'a> DiffLine<'a> {
     /// Create a new diff line from its raw component.
diff --git a/src/index.rs b/src/index.rs
index 51d28da75a..ced59989b5 100644
--- a/src/index.rs
+++ b/src/index.rs
@@ -420,7 +420,8 @@ impl Drop for Index {
     }
 }
 
-impl<'index> Iterator<IndexEntry> for IndexEntries<'index> {
+impl<'index> Iterator for IndexEntries<'index> {
+    type Item = IndexEntry;
     fn next(&mut self) -> Option<IndexEntry> {
         self.range.next().map(|i| self.index.get(i).unwrap())
     }
diff --git a/src/lib.rs b/src/lib.rs
index 12a64c39f7..9d9957018a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -64,6 +64,7 @@
 //! itself.
 
 #![feature(macro_rules, unsafe_destructor, unboxed_closures)]
+#![feature(associated_types)]
 #![deny(missing_docs)]
 #![cfg_attr(test, deny(warnings))]
 
diff --git a/src/note.rs b/src/note.rs
index 9fe29496ce..2b2e72fc3e 100644
--- a/src/note.rs
+++ b/src/note.rs
@@ -79,7 +79,8 @@ impl<'repo> Notes<'repo> {
     }
 }
 
-impl<'repo> Iterator<(Oid, Oid)> for Notes<'repo> {
+impl<'repo> Iterator for Notes<'repo> {
+    type Item = (Oid, Oid);
     fn next(&mut self) -> Option<(Oid, Oid)> {
         let mut note_id = raw::git_oid { id: [0; raw::GIT_OID_RAWSZ] };
         let mut annotated_id = note_id;
diff --git a/src/pathspec.rs b/src/pathspec.rs
index abfe40d745..be6844b386 100644
--- a/src/pathspec.rs
+++ b/src/pathspec.rs
@@ -38,7 +38,7 @@ pub struct PathspecFailedEntries<'list> {
 impl Pathspec {
     /// Creates a new pathspec from a list of specs to match against.
     pub fn new<I, T>(specs: I) -> Result<Pathspec, Error>
-                     where T: ToCStr, I: Iterator<T> {
+                     where T: ToCStr, I: Iterator<Item=T> {
         let strs = specs.map(|s| s.to_c_str()).collect::<Vec<_>>();
         let ptrs = strs.iter().map(|c| c.as_ptr()).collect::<Vec<_>>();
         let arr = raw::git_strarray {
@@ -222,44 +222,47 @@ impl<'ps> Drop for PathspecMatchList<'ps> {
     }
 }
 
-impl<'list> Iterator<&'list [u8]> for PathspecEntries<'list> {
+impl<'list> Iterator for PathspecEntries<'list> {
+    type Item = &'list [u8];
     fn next(&mut self) -> Option<&'list [u8]> {
         self.range.next().and_then(|i| self.list.entry(i))
     }
     fn size_hint(&self) -> (uint, Option<uint>) { self.range.size_hint() }
 }
-impl<'list> DoubleEndedIterator<&'list [u8]> for PathspecEntries<'list> {
+impl<'list> DoubleEndedIterator for PathspecEntries<'list> {
     fn next_back(&mut self) -> Option<&'list [u8]> {
         self.range.next_back().and_then(|i| self.list.entry(i))
     }
 }
-impl<'list> ExactSizeIterator<&'list [u8]> for PathspecEntries<'list> {}
+impl<'list> ExactSizeIterator for PathspecEntries<'list> {}
 
-impl<'list> Iterator<DiffDelta<'list>> for PathspecDiffEntries<'list> {
+impl<'list> Iterator for PathspecDiffEntries<'list> {
+    type Item = DiffDelta<'list>;
     fn next(&mut self) -> Option<DiffDelta<'list>> {
         self.range.next().and_then(|i| self.list.diff_entry(i))
     }
     fn size_hint(&self) -> (uint, Option<uint>) { self.range.size_hint() }
 }
-impl<'list> DoubleEndedIterator<DiffDelta<'list>> for PathspecDiffEntries<'list> {
+impl<'list> DoubleEndedIterator for PathspecDiffEntries<'list> {
     fn next_back(&mut self) -> Option<DiffDelta<'list>> {
         self.range.next_back().and_then(|i| self.list.diff_entry(i))
     }
 }
-impl<'list> ExactSizeIterator<DiffDelta<'list>> for PathspecDiffEntries<'list> {}
+impl<'list> ExactSizeIterator for PathspecDiffEntries<'list> {}
 
-impl<'list> Iterator<&'list [u8]> for PathspecFailedEntries<'list> {
+impl<'list> Iterator for PathspecFailedEntries<'list> {
+    type Item = &'list [u8];
     fn next(&mut self) -> Option<&'list [u8]> {
         self.range.next().and_then(|i| self.list.failed_entry(i))
     }
     fn size_hint(&self) -> (uint, Option<uint>) { self.range.size_hint() }
 }
-impl<'list> DoubleEndedIterator<&'list [u8]> for PathspecFailedEntries<'list> {
+impl<'list> DoubleEndedIterator for PathspecFailedEntries<'list> {
     fn next_back(&mut self) -> Option<&'list [u8]> {
         self.range.next_back().and_then(|i| self.list.failed_entry(i))
     }
 }
-impl<'list> ExactSizeIterator<&'list [u8]> for PathspecFailedEntries<'list> {}
+impl<'list> ExactSizeIterator for PathspecFailedEntries<'list> {}
 
 #[cfg(test)]
 mod tests {
diff --git a/src/reference.rs b/src/reference.rs
index 2b3fe2ac49..2d38ed1c8c 100644
--- a/src/reference.rs
+++ b/src/reference.rs
@@ -226,7 +226,8 @@ impl<'repo> References<'repo> {
     }
 }
 
-impl<'repo> Iterator<Reference<'repo>> for References<'repo> {
+impl<'repo> Iterator for References<'repo> {
+    type Item = Reference<'repo>;
     fn next(&mut self) -> Option<Reference<'repo>> {
         let mut out = 0 as *mut raw::git_reference;
         if unsafe { raw::git_reference_next(&mut out, self.raw) == 0 } {
@@ -257,7 +258,8 @@ impl<'repo> ReferenceNames<'repo> {
     }
 }
 
-impl<'repo> Iterator<&'repo str> for ReferenceNames<'repo> {
+impl<'repo> Iterator for ReferenceNames<'repo> {
+    type Item = &'repo str;
     fn next(&mut self) -> Option<&'repo str> {
         let mut out = 0 as *const libc::c_char;
         if unsafe { raw::git_reference_next_name(&mut out, self.inner.raw) == 0 } {
diff --git a/src/remote.rs b/src/remote.rs
index 5c9f18d382..5e9bbc231b 100644
--- a/src/remote.rs
+++ b/src/remote.rs
@@ -168,8 +168,8 @@ impl<'repo, 'cb> Remote<'repo, 'cb> {
     }
 
     /// Set the remote's list of fetch refspecs
-    pub fn set_fetch_refspecs<T: ToCStr, I: Iterator<T>>(&mut self, i: I)
-                                                         -> Result<(), Error> {
+    pub fn set_fetch_refspecs<T: ToCStr, I: Iterator<Item=T>>(&mut self, i: I)
+                                                              -> Result<(), Error> {
         let v = i.map(|t| t.to_c_str()).collect::<Vec<CString>>();
         let v2 = v.iter().map(|v| v.as_ptr()).collect::<Vec<*const libc::c_char>>();
         let mut arr = raw::git_strarray {
@@ -184,8 +184,8 @@ impl<'repo, 'cb> Remote<'repo, 'cb> {
     }
 
     /// Set the remote's list of push refspecs
-    pub fn set_push_refspecs<T: ToCStr, I: Iterator<T>>(&mut self, i: I)
-                                                         -> Result<(), Error> {
+    pub fn set_push_refspecs<T: ToCStr, I: Iterator<Item=T>>(&mut self, i: I)
+                                                             -> Result<(), Error> {
         let v = i.map(|t| t.to_c_str()).collect::<Vec<CString>>();
         let v2 = v.iter().map(|v| v.as_ptr()).collect::<Vec<*const libc::c_char>>();
         let mut arr = raw::git_strarray {
@@ -329,7 +329,8 @@ impl<'repo, 'cb> Remote<'repo, 'cb> {
     }
 }
 
-impl<'a, 'b> Iterator<Refspec<'a>> for Refspecs<'a, 'b> {
+impl<'a, 'b> Iterator for Refspecs<'a, 'b> {
+    type Item = Refspec<'a>;
     fn next(&mut self) -> Option<Refspec<'a>> {
         if self.cur == self.cnt { return None }
         let ret = unsafe {
diff --git a/src/repo.rs b/src/repo.rs
index 9b2020eeea..341f4b2020 100644
--- a/src/repo.rs
+++ b/src/repo.rs
@@ -359,9 +359,9 @@ impl Repository {
     /// matching the provided pathspecs.
     pub fn reset_default<'a,
                          T: ToCStr,
-                         I: Iterator<T>>(&'a self,
-                                         target: Option<&Object<'a>>,
-                                         paths: I) -> Result<(), Error> {
+                         I: Iterator<Item=T>>(&'a self,
+                                              target: Option<&Object<'a>>,
+                                              paths: I) -> Result<(), Error> {
         let v = paths.map(|t| t.to_c_str()).collect::<Vec<CString>>();
         let v2 = v.iter().map(|v| v.as_ptr()).collect::<Vec<*const c_char>>();
         let mut arr = raw::git_strarray {
diff --git a/src/revwalk.rs b/src/revwalk.rs
index 211be5bb78..338d399b00 100644
--- a/src/revwalk.rs
+++ b/src/revwalk.rs
@@ -160,7 +160,8 @@ impl<'repo> Drop for Revwalk<'repo> {
     }
 }
 
-impl<'repo> Iterator<Oid> for Revwalk<'repo> {
+impl<'repo> Iterator for Revwalk<'repo> {
+    type Item = Oid;
     fn next(&mut self) -> Option<Oid> {
         let mut out: raw::git_oid = raw::git_oid{ id: [0; raw::GIT_OID_RAWSZ] };
         unsafe {
diff --git a/src/status.rs b/src/status.rs
index 789c466ea1..3ccee1e024 100644
--- a/src/status.rs
+++ b/src/status.rs
@@ -279,20 +279,21 @@ impl<'repo> Drop for Statuses<'repo> {
     }
 }
 
-impl<'a> Iterator<StatusEntry<'a>> for StatusIter<'a> {
+impl<'a> Iterator for StatusIter<'a> {
+    type Item = StatusEntry<'a>;
     fn next(&mut self) -> Option<StatusEntry<'a>> {
         self.range.next().and_then(|i| self.statuses.get(i))
     }
     fn size_hint(&self) -> (uint, Option<uint>) { self.range.size_hint() }
 }
 
-impl<'a> DoubleEndedIterator<StatusEntry<'a>> for StatusIter<'a> {
+impl<'a> DoubleEndedIterator for StatusIter<'a> {
     fn next_back(&mut self) -> Option<StatusEntry<'a>> {
         self.range.next_back().and_then(|i| self.statuses.get(i))
     }
 }
 
-impl<'a> ExactSizeIterator<StatusEntry<'a>> for StatusIter<'a> {}
+impl<'a> ExactSizeIterator for StatusIter<'a> {}
 
 impl<'statuses> StatusEntry<'statuses> {
     /// Create a new status entry from its raw component.
diff --git a/src/string_array.rs b/src/string_array.rs
index 793aa19544..47b3d3b156 100644
--- a/src/string_array.rs
+++ b/src/string_array.rs
@@ -68,7 +68,8 @@ impl StringArray {
     pub fn len(&self) -> uint { self.raw.count as uint }
 }
 
-impl<'a> Iterator<Option<&'a str>> for StringArrayItems<'a> {
+impl<'a> Iterator for StringArrayItems<'a> {
+    type Item = Option<&'a str>;
     fn next(&mut self) -> Option<Option<&'a str>> {
         if self.cur < self.arr.len() {
             self.cur += 1;
@@ -79,7 +80,8 @@ impl<'a> Iterator<Option<&'a str>> for StringArrayItems<'a> {
     }
 }
 
-impl<'a> Iterator<&'a [u8]> for StringArrayBytes<'a> {
+impl<'a> Iterator for StringArrayBytes<'a> {
+    type Item = &'a [u8];
     fn next(&mut self) -> Option<&'a [u8]> {
         if self.cur < self.arr.len() {
             self.cur += 1;