diff --git a/src/libsyntax/ext/deriving/clone.rs b/src/libsyntax/ext/deriving/clone.rs
index 6d598c95e3a..c8ba6b990e4 100644
--- a/src/libsyntax/ext/deriving/clone.rs
+++ b/src/libsyntax/ext/deriving/clone.rs
@@ -17,6 +17,7 @@ use ext::build;
 use ext::deriving::*;
 use codemap::{span, spanned};
 use ast_util;
+use opt_vec;
 
 use core::uint;
 
@@ -48,12 +49,13 @@ fn create_derived_clone_impl(cx: @ext_ctxt,
                              method: @method)
                           -> @item {
     let methods = [ method ];
-    let trait_path = [
+    let trait_path = ~[
         cx.ident_of(~"core"),
         cx.ident_of(~"clone"),
         cx.ident_of(~"Clone"),
     ];
-    create_derived_impl(cx, span, type_ident, generics, methods, trait_path)
+    let trait_path = build::mk_raw_path_global(span, trait_path);
+    create_derived_impl(cx, span, type_ident, generics, methods, trait_path, opt_vec::Empty)
 }
 // Creates a method from the given expression conforming to the signature of
 // the `clone` method.
diff --git a/src/libsyntax/ext/deriving/eq.rs b/src/libsyntax/ext/deriving/eq.rs
index 46eec2ede68..c427a206c2e 100644
--- a/src/libsyntax/ext/deriving/eq.rs
+++ b/src/libsyntax/ext/deriving/eq.rs
@@ -17,6 +17,7 @@ use ext::build;
 use ext::deriving::*;
 use codemap::{span, spanned};
 use ast_util;
+use opt_vec;
 
 use core::uint;
 
@@ -124,12 +125,13 @@ fn create_derived_eq_impl(cx: @ext_ctxt,
                           ne_method: @method)
                        -> @item {
     let methods = [ eq_method, ne_method ];
-    let trait_path = [
+    let trait_path = ~[
         cx.ident_of(~"core"),
         cx.ident_of(~"cmp"),
         cx.ident_of(~"Eq")
     ];
-    create_derived_impl(cx, span, type_ident, generics, methods, trait_path)
+    let trait_path = build::mk_raw_path_global(span, trait_path);
+    create_derived_impl(cx, span, type_ident, generics, methods, trait_path, opt_vec::Empty)
 }
 
 fn call_substructure_eq_method(cx: @ext_ctxt,
diff --git a/src/libsyntax/ext/deriving/iter_bytes.rs b/src/libsyntax/ext/deriving/iter_bytes.rs
index e832408dd2b..4124e6ee6c1 100644
--- a/src/libsyntax/ext/deriving/iter_bytes.rs
+++ b/src/libsyntax/ext/deriving/iter_bytes.rs
@@ -17,6 +17,7 @@ use ext::build;
 use ext::deriving::*;
 use codemap::{span, spanned};
 use ast_util;
+use opt_vec;
 
 use core::uint;
 
@@ -49,12 +50,13 @@ fn create_derived_iter_bytes_impl(cx: @ext_ctxt,
                                   method: @method)
                                -> @item {
     let methods = [ method ];
-    let trait_path = [
+    let trait_path = ~[
         cx.ident_of(~"core"),
         cx.ident_of(~"to_bytes"),
         cx.ident_of(~"IterBytes")
     ];
-    create_derived_impl(cx, span, type_ident, generics, methods, trait_path)
+    let trait_path = build::mk_raw_path_global(span, trait_path);
+    create_derived_impl(cx, span, type_ident, generics, methods, trait_path, opt_vec::Empty)
 }
 
 // Creates a method from the given set of statements conforming to the
diff --git a/src/libsyntax/ext/deriving/mod.rs b/src/libsyntax/ext/deriving/mod.rs
index 4337546930f..95bca7ff230 100644
--- a/src/libsyntax/ext/deriving/mod.rs
+++ b/src/libsyntax/ext/deriving/mod.rs
@@ -14,7 +14,7 @@
 use core::prelude::*;
 
 use ast;
-use ast::{TraitTyParamBound, Ty, bind_by_ref, deref, enum_def};
+use ast::{Ty, bind_by_ref, deref, enum_def};
 use ast::{expr, expr_match, ident, item, item_};
 use ast::{item_enum, item_impl, item_struct, Generics};
 use ast::{m_imm, meta_item, method};
@@ -153,12 +153,13 @@ pub fn create_self_type_with_params(cx: @ext_ctxt,
 }
 
 pub fn create_derived_impl(cx: @ext_ctxt,
-                       span: span,
-                       type_ident: ident,
-                       generics: &Generics,
-                       methods: &[@method],
-                       trait_path: &[ident])
-                    -> @item {
+                           span: span,
+                           type_ident: ident,
+                           generics: &Generics,
+                           methods: &[@method],
+                           trait_path: @ast::Path,
+                           mut impl_ty_params: opt_vec::OptVec<ast::TyParam>)
+                        -> @item {
     /*!
      *
      * Given that we are deriving a trait `Tr` for a type `T<'a, ...,
@@ -175,29 +176,16 @@ pub fn create_derived_impl(cx: @ext_ctxt,
         build::mk_lifetime(cx, l.span, l.ident)
     });
 
-    // Create the type parameters.
-    let impl_ty_params = generics.ty_params.map(|ty_param| {
-        let bound = build::mk_trait_ref_global(cx,
-                                               span,
-                                               trait_path.map(|x| *x));
-        let bounds = @opt_vec::with(TraitTyParamBound(bound));
-        build::mk_ty_param(cx, ty_param.ident, bounds)
-    });
-
     // Create the reference to the trait.
-    let trait_path = ast::Path {
-        span: span,
-        global: true,
-        idents: trait_path.map(|x| *x),
-        rp: None,
-        types: ~[]
+    let trait_ref = build::mk_trait_ref_(cx, trait_path);
+
+    // Create the type parameters.
+    for generics.ty_params.each |ty_param| {
+        let bounds = @opt_vec::with(
+            build::mk_trait_ty_param_bound_(cx, trait_path)
+        );
+        impl_ty_params.push(build::mk_ty_param(cx, ty_param.ident, bounds));
     };
-    let trait_path = @trait_path;
-    let trait_ref = ast::trait_ref {
-        path: trait_path,
-        ref_id: cx.next_id()
-    };
-    let trait_ref = @trait_ref;
 
     // Create the type of `self`.
     let self_type = create_self_type_with_params(cx,