diff --git a/src/test/auxiliary/method_self_arg2.rs b/src/test/auxiliary/method_self_arg2.rs
index e1e79b59e3e..eb4d62b01ad 100644
--- a/src/test/auxiliary/method_self_arg2.rs
+++ b/src/test/auxiliary/method_self_arg2.rs
@@ -32,7 +32,7 @@ impl Foo {
     }
 }
 
-pub trait Bar {
+pub trait Bar : Sized {
     fn foo1(&self);
     fn foo2(self);
     fn foo3(self: Box<Self>);
diff --git a/src/test/compile-fail/dst-sized-trait-param.rs b/src/test/compile-fail/dst-sized-trait-param.rs
index 750b475adb2..ea5becbf229 100644
--- a/src/test/compile-fail/dst-sized-trait-param.rs
+++ b/src/test/compile-fail/dst-sized-trait-param.rs
@@ -12,7 +12,7 @@
 // parameter, the corresponding value must be sized. Also that the
 // self type must be sized if appropriate.
 
-trait Foo<T> { fn take(self, x: &T) { } } // Note: T is sized
+trait Foo<T> : Sized { fn take(self, x: &T) { } } // Note: T is sized
 
 impl Foo<[int]> for uint { }
 //~^ ERROR the trait `core::kinds::Sized` is not implemented for the type `[int]`
diff --git a/src/test/compile-fail/issue-5543.rs b/src/test/compile-fail/issue-5543.rs
index bbd41b28f03..f970cdb1b83 100644
--- a/src/test/compile-fail/issue-5543.rs
+++ b/src/test/compile-fail/issue-5543.rs
@@ -15,5 +15,4 @@ fn main() {
     let r: Box<Foo> = box 5;
     let _m: Box<Foo> = r as Box<Foo>;
     //~^ ERROR `core::kinds::Sized` is not implemented for the type `Foo`
-    //~| ERROR `Foo` is not implemented for the type `Foo`
 }
diff --git a/src/test/compile-fail/regions-infer-bound-from-trait-self.rs b/src/test/compile-fail/regions-infer-bound-from-trait-self.rs
index 25fd20b6ec5..aeb003ca5d0 100644
--- a/src/test/compile-fail/regions-infer-bound-from-trait-self.rs
+++ b/src/test/compile-fail/regions-infer-bound-from-trait-self.rs
@@ -23,12 +23,12 @@ fn check_bound<'a,A:'a>(x: Inv<'a>, a: A) { }
 
 // In these case, `Self` inherits `'static`.
 
-trait InheritsFromStatic : 'static {
+trait InheritsFromStatic : Sized + 'static {
     fn foo1<'a>(self, x: Inv<'a>) {
         check_bound(x, self)
     }
 }
-trait InheritsFromStaticIndirectly : Static {
+trait InheritsFromStaticIndirectly : Sized + Static {
     fn foo1<'a>(self, x: Inv<'a>) {
         check_bound(x, self)
     }
@@ -37,13 +37,13 @@ trait InheritsFromStaticIndirectly : Static {
 
 // In these case, `Self` inherits `'a`.
 
-trait InheritsFromIs<'a> : 'a {
+trait InheritsFromIs<'a> : Sized + 'a {
     fn foo(self, x: Inv<'a>) {
         check_bound(x, self)
     }
 }
 
-trait InheritsFromIsIndirectly<'a> : Is<'a> {
+trait InheritsFromIsIndirectly<'a> : Sized + Is<'a> {
     fn foo(self, x: Inv<'a>) {
         check_bound(x, self)
     }
@@ -51,7 +51,7 @@ trait InheritsFromIsIndirectly<'a> : Is<'a> {
 
 // In this case, `Self` inherits nothing.
 
-trait InheritsFromNothing<'a> {
+trait InheritsFromNothing<'a> : Sized {
     fn foo(self, x: Inv<'a>) {
         check_bound(x, self)
             //~^ ERROR parameter type `Self` may not live long enough
diff --git a/src/test/compile-fail/trait-matching-lifetimes.rs b/src/test/compile-fail/trait-matching-lifetimes.rs
index f1b30166b5e..333730e0c4b 100644
--- a/src/test/compile-fail/trait-matching-lifetimes.rs
+++ b/src/test/compile-fail/trait-matching-lifetimes.rs
@@ -16,7 +16,7 @@ struct Foo<'a,'b> {
     y: &'b int,
 }
 
-trait Tr {
+trait Tr : Sized {
     fn foo(x: Self) {}
 }
 
diff --git a/src/test/compile-fail/trait-safety-fn-body.rs b/src/test/compile-fail/trait-safety-fn-body.rs
index d174092e4d0..f894e2ee28e 100644
--- a/src/test/compile-fail/trait-safety-fn-body.rs
+++ b/src/test/compile-fail/trait-safety-fn-body.rs
@@ -11,7 +11,7 @@
 // Check that an unsafe impl does not imply that unsafe actions are
 // legal in the methods.
 
-unsafe trait UnsafeTrait {
+unsafe trait UnsafeTrait : Sized {
     fn foo(self) { }
 }
 
diff --git a/src/test/compile-fail/type-params-in-different-spaces-2.rs b/src/test/compile-fail/type-params-in-different-spaces-2.rs
index 9be64bf5346..3a4cc9e874e 100644
--- a/src/test/compile-fail/type-params-in-different-spaces-2.rs
+++ b/src/test/compile-fail/type-params-in-different-spaces-2.rs
@@ -11,7 +11,7 @@
 // Test static calls to make sure that we align the Self and input
 // type parameters on a trait correctly.
 
-trait Tr<T> {
+trait Tr<T> : Sized {
     fn op(T) -> Self;
 }
 
diff --git a/src/test/compile-fail/type-params-in-different-spaces-3.rs b/src/test/compile-fail/type-params-in-different-spaces-3.rs
index a3d69d53ba9..c113e1b7815 100644
--- a/src/test/compile-fail/type-params-in-different-spaces-3.rs
+++ b/src/test/compile-fail/type-params-in-different-spaces-3.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-trait Tr {
+trait Tr : Sized {
     fn test<X>(u: X) -> Self {
         u   //~ ERROR mismatched types
     }
diff --git a/src/test/compile-fail/unsized4.rs b/src/test/compile-fail/unsized4.rs
index 0537fc1f94a..f9ece8e6843 100644
--- a/src/test/compile-fail/unsized4.rs
+++ b/src/test/compile-fail/unsized4.rs
@@ -10,8 +10,7 @@
 
 // Test that bounds are sized-compatible.
 
-trait T {}
-
+trait T : Sized {}
 fn f<Sized? Y: T>() {
 //~^ERROR incompatible bounds on `Y`, bound `T` does not allow unsized type
 }
diff --git a/src/test/debuginfo/issue7712.rs b/src/test/debuginfo/issue7712.rs
index 948048ec272..94458a7fb4b 100644
--- a/src/test/debuginfo/issue7712.rs
+++ b/src/test/debuginfo/issue7712.rs
@@ -11,7 +11,7 @@
 // compile-flags:--debuginfo=1
 // min-lldb-version: 310
 
-pub trait TraitWithDefaultMethod {
+pub trait TraitWithDefaultMethod : Sized {
     fn method(self) {
         ()
     }
diff --git a/src/test/debuginfo/self-in-default-method.rs b/src/test/debuginfo/self-in-default-method.rs
index f8ef5b3d2fc..87884d2f956 100644
--- a/src/test/debuginfo/self-in-default-method.rs
+++ b/src/test/debuginfo/self-in-default-method.rs
@@ -118,7 +118,7 @@ struct Struct {
     x: int
 }
 
-trait Trait {
+trait Trait : Sized {
     fn self_by_ref(&self, arg1: int, arg2: int) -> int {
         zzz(); // #break
         arg1 + arg2
diff --git a/src/test/debuginfo/self-in-generic-default-method.rs b/src/test/debuginfo/self-in-generic-default-method.rs
index c2594df7d35..62b5e6872ee 100644
--- a/src/test/debuginfo/self-in-generic-default-method.rs
+++ b/src/test/debuginfo/self-in-generic-default-method.rs
@@ -118,7 +118,7 @@ struct Struct {
     x: int
 }
 
-trait Trait {
+trait Trait : Sized {
 
     fn self_by_ref<T>(&self, arg1: int, arg2: T) -> int {
         zzz(); // #break
diff --git a/src/test/run-pass/associated-types-impl-redirect.rs b/src/test/run-pass/associated-types-impl-redirect.rs
index a28cf346336..ce7f5dde2ad 100644
--- a/src/test/run-pass/associated-types-impl-redirect.rs
+++ b/src/test/run-pass/associated-types-impl-redirect.rs
@@ -19,6 +19,7 @@
 #![feature(associated_types, lang_items, unboxed_closures)]
 #![no_implicit_prelude]
 
+use std::kinds::Sized;
 use std::option::Option::{None, Some, mod};
 
 trait Iterator {
@@ -27,7 +28,7 @@ trait Iterator {
     fn next(&mut self) -> Option<Self::Item>;
 }
 
-trait IteratorExt: Iterator {
+trait IteratorExt: Iterator + Sized {
     fn by_ref(&mut self) -> ByRef<Self> {
         ByRef(self)
     }
diff --git a/src/test/run-pass/associated-types-projection-bound-in-supertraits.rs b/src/test/run-pass/associated-types-projection-bound-in-supertraits.rs
index 83686d92a7c..92daee5225d 100644
--- a/src/test/run-pass/associated-types-projection-bound-in-supertraits.rs
+++ b/src/test/run-pass/associated-types-projection-bound-in-supertraits.rs
@@ -21,7 +21,7 @@ trait Not {
     fn not(self) -> Self::Result;
 }
 
-trait Int: Not<Result=Self> {
+trait Int: Not<Result=Self> + Sized {
     fn count_ones(self) -> uint;
     fn count_zeros(self) -> uint {
         // neither works
diff --git a/src/test/run-pass/associated-types-where-clause-impl-ambiguity.rs b/src/test/run-pass/associated-types-where-clause-impl-ambiguity.rs
index 062d37556ec..7afaf290424 100644
--- a/src/test/run-pass/associated-types-where-clause-impl-ambiguity.rs
+++ b/src/test/run-pass/associated-types-where-clause-impl-ambiguity.rs
@@ -19,6 +19,7 @@
 #![feature(associated_types, lang_items, unboxed_closures)]
 #![no_implicit_prelude]
 
+use std::kinds::Sized;
 use std::option::Option::{None, Some, mod};
 
 trait Iterator {
@@ -27,7 +28,7 @@ trait Iterator {
     fn next(&mut self) -> Option<Self::Item>;
 }
 
-trait IteratorExt: Iterator {
+trait IteratorExt: Iterator + Sized {
     fn by_ref(&mut self) -> ByRef<Self> {
         ByRef(self)
     }
diff --git a/src/test/run-pass/bug-7183-generics.rs b/src/test/run-pass/bug-7183-generics.rs
index 8c4d10a2d59..bf8d303f341 100644
--- a/src/test/run-pass/bug-7183-generics.rs
+++ b/src/test/run-pass/bug-7183-generics.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-trait Speak {
+trait Speak : Sized {
     fn say(&self, s:&str) -> String;
     fn hi(&self) -> String { hello(self) }
 }
diff --git a/src/test/run-pass/builtin-superkinds-self-type.rs b/src/test/run-pass/builtin-superkinds-self-type.rs
index 1c156f6551c..ab775132dde 100644
--- a/src/test/run-pass/builtin-superkinds-self-type.rs
+++ b/src/test/run-pass/builtin-superkinds-self-type.rs
@@ -11,7 +11,7 @@
 // Tests the ability for the Self type in default methods to use
 // capabilities granted by builtin kinds as supertraits.
 
-trait Foo : Send {
+trait Foo : Send + Sized {
     fn foo(self, tx: Sender<Self>) {
         tx.send(self);
     }
diff --git a/src/test/run-pass/default-method-supertrait-vtable.rs b/src/test/run-pass/default-method-supertrait-vtable.rs
index 1b2b17f9917..727cada21fa 100644
--- a/src/test/run-pass/default-method-supertrait-vtable.rs
+++ b/src/test/run-pass/default-method-supertrait-vtable.rs
@@ -21,7 +21,7 @@ trait Y {
 }
 
 
-trait Z: Y {
+trait Z: Y + Sized {
     fn x(self) -> int {
         require_y(self)
     }
diff --git a/src/test/run-pass/issue-7320.rs b/src/test/run-pass/issue-7320.rs
index c7087f8e3a8..bd57a3956c7 100644
--- a/src/test/run-pass/issue-7320.rs
+++ b/src/test/run-pass/issue-7320.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 
-trait Foo {
+trait Foo : Sized {
     fn foo(self: Box<Self>) { bar(self as Box<Foo>); }
 }
 
diff --git a/src/test/run-pass/issue-8171-default-method-self-inherit-builtin-trait.rs b/src/test/run-pass/issue-8171-default-method-self-inherit-builtin-trait.rs
index aaf2ecb7129..3238c24163e 100644
--- a/src/test/run-pass/issue-8171-default-method-self-inherit-builtin-trait.rs
+++ b/src/test/run-pass/issue-8171-default-method-self-inherit-builtin-trait.rs
@@ -16,7 +16,7 @@
 
 fn require_send<T: Send>(_: T){}
 
-trait TragicallySelfIsNotSend: Send {
+trait TragicallySelfIsNotSend: Send + Sized {
     fn x(self) {
         require_send(self);
     }
diff --git a/src/test/run-pass/method-self-arg-trait.rs b/src/test/run-pass/method-self-arg-trait.rs
index 36dfe83a9eb..29d100beb06 100644
--- a/src/test/run-pass/method-self-arg-trait.rs
+++ b/src/test/run-pass/method-self-arg-trait.rs
@@ -16,7 +16,7 @@ struct Foo;
 
 impl Copy for Foo {}
 
-trait Bar {
+trait Bar : Sized {
     fn foo1(&self);
     fn foo2(self);
     fn foo3(self: Box<Self>);
diff --git a/src/test/run-pass/self-in-mut-slot-default-method.rs b/src/test/run-pass/self-in-mut-slot-default-method.rs
index b4a46f34015..bced8012b68 100644
--- a/src/test/run-pass/self-in-mut-slot-default-method.rs
+++ b/src/test/run-pass/self-in-mut-slot-default-method.rs
@@ -13,7 +13,7 @@ struct X {
     a: int
 }
 
-trait Changer {
+trait Changer : Sized {
     fn change(mut self) -> Self {
         self.set_to(55);
         self