diff --git a/src/dvec.rs b/src/dvec.rs
index 0a6a9b0d..ace36cbc 100644
--- a/src/dvec.rs
+++ b/src/dvec.rs
@@ -46,8 +46,8 @@ impl<N> IterableMut<N> for DVec<N> {
     }
 }
 
-impl<N, Iter: Iterator<N>> FromIterator<N, Iter> for DVec<N> {
-    fn from_iterator(mut param: &mut Iter) -> DVec<N> {
+impl<N> FromIterator<N> for DVec<N> {
+    fn from_iterator<I: Iterator<N>>(mut param: &mut I) -> DVec<N> {
         let mut res = DVec { at: ~[] };
 
         for e in param {
diff --git a/src/vec0_spec.rs b/src/vec0_spec.rs
index 00e0bfd6..5bbcb887 100644
--- a/src/vec0_spec.rs
+++ b/src/vec0_spec.rs
@@ -231,9 +231,9 @@ impl<N: Clone + One> One for vec::Vec0<N> {
     }
 }
 
-impl<N, Iter: Iterator<N>> FromIterator<N, Iter> for vec::Vec0<N> {
+impl<N> FromIterator<N> for vec::Vec0<N> {
     #[inline]
-    fn from_iterator(_: &mut Iter) -> vec::Vec0<N> {
+    fn from_iterator<I: Iterator<N>>(_: &mut I) -> vec::Vec0<N> {
         vec::Vec0
     }
 }
diff --git a/src/vec_macros.rs b/src/vec_macros.rs
index 4cc92fea..d978da6c 100644
--- a/src/vec_macros.rs
+++ b/src/vec_macros.rs
@@ -480,9 +480,9 @@ macro_rules! one_impl(
 
 macro_rules! from_iterator_impl(
     ($t: ident, $param0: ident $(, $paramN: ident)*) => (
-        impl<N, Iter: Iterator<N>> FromIterator<N, Iter> for $t<N> {
+        impl<N> FromIterator<N> for $t<N> {
             #[inline]
-            fn from_iterator($param0: &mut Iter) -> $t<N> {
+            fn from_iterator<I: Iterator<N>>($param0: &mut I) -> $t<N> {
                 $t::new($param0.next().unwrap() $(, $paramN.next().unwrap())*)
             }
         }