diff --git a/tests/ui/async-await/in-trait/async-associated-types.rs b/tests/ui/async-await/in-trait/async-associated-types.rs
index 974f5aaff83..89ca4039bce 100644
--- a/tests/ui/async-await/in-trait/async-associated-types.rs
+++ b/tests/ui/async-await/in-trait/async-associated-types.rs
@@ -1,5 +1,7 @@
 // check-pass
 // edition: 2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![feature(impl_trait_projections)]
diff --git a/tests/ui/async-await/in-trait/async-associated-types2.rs b/tests/ui/async-await/in-trait/async-associated-types2.rs
index e546a0579c6..cdecb02bfad 100644
--- a/tests/ui/async-await/in-trait/async-associated-types2.rs
+++ b/tests/ui/async-await/in-trait/async-associated-types2.rs
@@ -1,5 +1,7 @@
 // check-pass
 // edition: 2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![feature(type_alias_impl_trait)]
diff --git a/tests/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.stderr b/tests/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.current.stderr
similarity index 84%
rename from tests/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.stderr
rename to tests/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.current.stderr
index 168ef8e9ee4..b5ace9ada4f 100644
--- a/tests/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.stderr
+++ b/tests/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.current.stderr
@@ -1,11 +1,11 @@
 error[E0053]: method `foo` has an incompatible type for trait
-  --> $DIR/async-example-desugared-boxed-in-trait.rs:15:28
+  --> $DIR/async-example-desugared-boxed-in-trait.rs:17:28
    |
 LL |     async fn foo(&self) -> i32 {
    |                            ^^^ expected `Pin<Box<dyn Future<Output = i32>>>`, found future
    |
 note: type in trait
-  --> $DIR/async-example-desugared-boxed-in-trait.rs:11:22
+  --> $DIR/async-example-desugared-boxed-in-trait.rs:13:22
    |
 LL |     fn foo(&self) -> Pin<Box<dyn Future<Output = i32> + '_>>;
    |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.next.stderr b/tests/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.next.stderr
new file mode 100644
index 00000000000..b5ace9ada4f
--- /dev/null
+++ b/tests/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.next.stderr
@@ -0,0 +1,17 @@
+error[E0053]: method `foo` has an incompatible type for trait
+  --> $DIR/async-example-desugared-boxed-in-trait.rs:17:28
+   |
+LL |     async fn foo(&self) -> i32 {
+   |                            ^^^ expected `Pin<Box<dyn Future<Output = i32>>>`, found future
+   |
+note: type in trait
+  --> $DIR/async-example-desugared-boxed-in-trait.rs:13:22
+   |
+LL |     fn foo(&self) -> Pin<Box<dyn Future<Output = i32> + '_>>;
+   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: expected signature `fn(&i32) -> Pin<Box<dyn Future<Output = i32>>>`
+              found signature `fn(&i32) -> impl Future<Output = i32>`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0053`.
diff --git a/tests/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.rs b/tests/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.rs
index 38ba297189c..7b53379b24b 100644
--- a/tests/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.rs
+++ b/tests/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.rs
@@ -1,4 +1,6 @@
 // edition: 2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![feature(return_position_impl_trait_in_trait)]
diff --git a/tests/ui/async-await/in-trait/async-example-desugared-boxed.stderr b/tests/ui/async-await/in-trait/async-example-desugared-boxed.current.stderr
similarity index 88%
rename from tests/ui/async-await/in-trait/async-example-desugared-boxed.stderr
rename to tests/ui/async-await/in-trait/async-example-desugared-boxed.current.stderr
index 60fa534a64f..6c0b5859186 100644
--- a/tests/ui/async-await/in-trait/async-example-desugared-boxed.stderr
+++ b/tests/ui/async-await/in-trait/async-example-desugared-boxed.current.stderr
@@ -1,5 +1,5 @@
 error: method `foo` should be async because the method from the trait is async
-  --> $DIR/async-example-desugared-boxed.rs:15:5
+  --> $DIR/async-example-desugared-boxed.rs:17:5
    |
 LL |     async fn foo(&self) -> i32;
    |     --------------------------- required because the trait method is async
diff --git a/tests/ui/async-await/in-trait/async-example-desugared-boxed.next.stderr b/tests/ui/async-await/in-trait/async-example-desugared-boxed.next.stderr
new file mode 100644
index 00000000000..6c0b5859186
--- /dev/null
+++ b/tests/ui/async-await/in-trait/async-example-desugared-boxed.next.stderr
@@ -0,0 +1,11 @@
+error: method `foo` should be async because the method from the trait is async
+  --> $DIR/async-example-desugared-boxed.rs:17:5
+   |
+LL |     async fn foo(&self) -> i32;
+   |     --------------------------- required because the trait method is async
+...
+LL |     fn foo(&self) -> Pin<Box<dyn Future<Output = i32> + '_>> {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/in-trait/async-example-desugared-boxed.rs b/tests/ui/async-await/in-trait/async-example-desugared-boxed.rs
index 1b1b3cffd58..916488ffafa 100644
--- a/tests/ui/async-await/in-trait/async-example-desugared-boxed.rs
+++ b/tests/ui/async-await/in-trait/async-example-desugared-boxed.rs
@@ -1,4 +1,6 @@
 // edition: 2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![feature(return_position_impl_trait_in_trait)]
diff --git a/tests/ui/async-await/in-trait/async-example-desugared-extra.rs b/tests/ui/async-await/in-trait/async-example-desugared-extra.rs
index 81e1e59a362..edac0b374a3 100644
--- a/tests/ui/async-await/in-trait/async-example-desugared-extra.rs
+++ b/tests/ui/async-await/in-trait/async-example-desugared-extra.rs
@@ -1,5 +1,7 @@
 // check-pass
 // edition: 2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![feature(return_position_impl_trait_in_trait)]
diff --git a/tests/ui/async-await/in-trait/async-example-desugared-in-trait.rs b/tests/ui/async-await/in-trait/async-example-desugared-in-trait.rs
index feeda719e03..934f7643dd1 100644
--- a/tests/ui/async-await/in-trait/async-example-desugared-in-trait.rs
+++ b/tests/ui/async-await/in-trait/async-example-desugared-in-trait.rs
@@ -1,5 +1,7 @@
 // check-pass
 // edition: 2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![feature(return_position_impl_trait_in_trait)]
diff --git a/tests/ui/async-await/in-trait/async-example-desugared-manual.stderr b/tests/ui/async-await/in-trait/async-example-desugared-manual.current.stderr
similarity index 86%
rename from tests/ui/async-await/in-trait/async-example-desugared-manual.stderr
rename to tests/ui/async-await/in-trait/async-example-desugared-manual.current.stderr
index 567a36a86d1..0d2551ab84f 100644
--- a/tests/ui/async-await/in-trait/async-example-desugared-manual.stderr
+++ b/tests/ui/async-await/in-trait/async-example-desugared-manual.current.stderr
@@ -1,5 +1,5 @@
 error: method `foo` should be async because the method from the trait is async
-  --> $DIR/async-example-desugared-manual.rs:23:5
+  --> $DIR/async-example-desugared-manual.rs:25:5
    |
 LL |     async fn foo(&self) -> i32;
    |     --------------------------- required because the trait method is async
diff --git a/tests/ui/async-await/in-trait/async-example-desugared-manual.next.stderr b/tests/ui/async-await/in-trait/async-example-desugared-manual.next.stderr
new file mode 100644
index 00000000000..0d2551ab84f
--- /dev/null
+++ b/tests/ui/async-await/in-trait/async-example-desugared-manual.next.stderr
@@ -0,0 +1,11 @@
+error: method `foo` should be async because the method from the trait is async
+  --> $DIR/async-example-desugared-manual.rs:25:5
+   |
+LL |     async fn foo(&self) -> i32;
+   |     --------------------------- required because the trait method is async
+...
+LL |     fn foo(&self) -> MyFuture {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/async-await/in-trait/async-example-desugared-manual.rs b/tests/ui/async-await/in-trait/async-example-desugared-manual.rs
index 71473e7455f..4883828d32f 100644
--- a/tests/ui/async-await/in-trait/async-example-desugared-manual.rs
+++ b/tests/ui/async-await/in-trait/async-example-desugared-manual.rs
@@ -1,4 +1,6 @@
 // edition: 2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![feature(return_position_impl_trait_in_trait)]
diff --git a/tests/ui/async-await/in-trait/async-example-desugared.rs b/tests/ui/async-await/in-trait/async-example-desugared.rs
index fb92ec78674..214171b2e2c 100644
--- a/tests/ui/async-await/in-trait/async-example-desugared.rs
+++ b/tests/ui/async-await/in-trait/async-example-desugared.rs
@@ -1,5 +1,7 @@
 // check-pass
 // edition: 2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![feature(return_position_impl_trait_in_trait)]
diff --git a/tests/ui/async-await/in-trait/async-recursive-generic.stderr b/tests/ui/async-await/in-trait/async-recursive-generic.current.stderr
similarity index 91%
rename from tests/ui/async-await/in-trait/async-recursive-generic.stderr
rename to tests/ui/async-await/in-trait/async-recursive-generic.current.stderr
index cab173bdd5b..67b491f19d2 100644
--- a/tests/ui/async-await/in-trait/async-recursive-generic.stderr
+++ b/tests/ui/async-await/in-trait/async-recursive-generic.current.stderr
@@ -1,5 +1,5 @@
 error[E0733]: recursion in an `async fn` requires boxing
-  --> $DIR/async-recursive-generic.rs:11:48
+  --> $DIR/async-recursive-generic.rs:13:48
    |
 LL |     async fn foo_recursive(&self, n: usize) -> T {
    |                                                ^ recursive `async fn`
diff --git a/tests/ui/async-await/in-trait/async-recursive-generic.next.stderr b/tests/ui/async-await/in-trait/async-recursive-generic.next.stderr
new file mode 100644
index 00000000000..67b491f19d2
--- /dev/null
+++ b/tests/ui/async-await/in-trait/async-recursive-generic.next.stderr
@@ -0,0 +1,12 @@
+error[E0733]: recursion in an `async fn` requires boxing
+  --> $DIR/async-recursive-generic.rs:13:48
+   |
+LL |     async fn foo_recursive(&self, n: usize) -> T {
+   |                                                ^ recursive `async fn`
+   |
+   = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future`
+   = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0733`.
diff --git a/tests/ui/async-await/in-trait/async-recursive-generic.rs b/tests/ui/async-await/in-trait/async-recursive-generic.rs
index 6839abd381c..64c6ba15c0c 100644
--- a/tests/ui/async-await/in-trait/async-recursive-generic.rs
+++ b/tests/ui/async-await/in-trait/async-recursive-generic.rs
@@ -1,4 +1,6 @@
 // edition: 2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![allow(incomplete_features)]
diff --git a/tests/ui/async-await/in-trait/async-recursive.stderr b/tests/ui/async-await/in-trait/async-recursive.current.stderr
similarity index 93%
rename from tests/ui/async-await/in-trait/async-recursive.stderr
rename to tests/ui/async-await/in-trait/async-recursive.current.stderr
index 9feff37b3fe..85af27e3746 100644
--- a/tests/ui/async-await/in-trait/async-recursive.stderr
+++ b/tests/ui/async-await/in-trait/async-recursive.current.stderr
@@ -1,5 +1,5 @@
 error[E0733]: recursion in an `async fn` requires boxing
-  --> $DIR/async-recursive.rs:11:48
+  --> $DIR/async-recursive.rs:13:48
    |
 LL |     async fn foo_recursive(&self, n: usize) -> i32 {
    |                                                ^^^ recursive `async fn`
diff --git a/tests/ui/async-await/in-trait/async-recursive.next.stderr b/tests/ui/async-await/in-trait/async-recursive.next.stderr
new file mode 100644
index 00000000000..85af27e3746
--- /dev/null
+++ b/tests/ui/async-await/in-trait/async-recursive.next.stderr
@@ -0,0 +1,12 @@
+error[E0733]: recursion in an `async fn` requires boxing
+  --> $DIR/async-recursive.rs:13:48
+   |
+LL |     async fn foo_recursive(&self, n: usize) -> i32 {
+   |                                                ^^^ recursive `async fn`
+   |
+   = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future`
+   = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0733`.
diff --git a/tests/ui/async-await/in-trait/async-recursive.rs b/tests/ui/async-await/in-trait/async-recursive.rs
index 61119f8095b..d928909e3ae 100644
--- a/tests/ui/async-await/in-trait/async-recursive.rs
+++ b/tests/ui/async-await/in-trait/async-recursive.rs
@@ -1,4 +1,6 @@
 // edition: 2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![allow(incomplete_features)]
diff --git a/tests/ui/async-await/in-trait/bad-signatures.stderr b/tests/ui/async-await/in-trait/bad-signatures.current.stderr
similarity index 89%
rename from tests/ui/async-await/in-trait/bad-signatures.stderr
rename to tests/ui/async-await/in-trait/bad-signatures.current.stderr
index e0ba7b53ec4..5a05b080c3e 100644
--- a/tests/ui/async-await/in-trait/bad-signatures.stderr
+++ b/tests/ui/async-await/in-trait/bad-signatures.current.stderr
@@ -1,11 +1,11 @@
 error: expected identifier, found keyword `self`
-  --> $DIR/bad-signatures.rs:7:23
+  --> $DIR/bad-signatures.rs:9:23
    |
 LL |     async fn bar(&abc self);
    |                       ^^^^ expected identifier, found keyword
 
 error: expected one of `:`, `@`, or `|`, found keyword `self`
-  --> $DIR/bad-signatures.rs:7:23
+  --> $DIR/bad-signatures.rs:9:23
    |
 LL |     async fn bar(&abc self);
    |                  -----^^^^
@@ -14,7 +14,7 @@ LL |     async fn bar(&abc self);
    |                  help: declare the type after the parameter binding: `<identifier>: <type>`
 
 warning: the feature `async_fn_in_trait` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/bad-signatures.rs:3:12
+  --> $DIR/bad-signatures.rs:5:12
    |
 LL | #![feature(async_fn_in_trait)]
    |            ^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/async-await/in-trait/bad-signatures.next.stderr b/tests/ui/async-await/in-trait/bad-signatures.next.stderr
new file mode 100644
index 00000000000..5a05b080c3e
--- /dev/null
+++ b/tests/ui/async-await/in-trait/bad-signatures.next.stderr
@@ -0,0 +1,26 @@
+error: expected identifier, found keyword `self`
+  --> $DIR/bad-signatures.rs:9:23
+   |
+LL |     async fn bar(&abc self);
+   |                       ^^^^ expected identifier, found keyword
+
+error: expected one of `:`, `@`, or `|`, found keyword `self`
+  --> $DIR/bad-signatures.rs:9:23
+   |
+LL |     async fn bar(&abc self);
+   |                  -----^^^^
+   |                  |    |
+   |                  |    expected one of `:`, `@`, or `|`
+   |                  help: declare the type after the parameter binding: `<identifier>: <type>`
+
+warning: the feature `async_fn_in_trait` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/bad-signatures.rs:5:12
+   |
+LL | #![feature(async_fn_in_trait)]
+   |            ^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+error: aborting due to 2 previous errors; 1 warning emitted
+
diff --git a/tests/ui/async-await/in-trait/bad-signatures.rs b/tests/ui/async-await/in-trait/bad-signatures.rs
index b86f1d1c135..e0093be8cb3 100644
--- a/tests/ui/async-await/in-trait/bad-signatures.rs
+++ b/tests/ui/async-await/in-trait/bad-signatures.rs
@@ -1,4 +1,6 @@
 // edition:2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 //~^ WARN the feature `async_fn_in_trait` is incomplete
diff --git a/tests/ui/async-await/in-trait/early-bound-1.rs b/tests/ui/async-await/in-trait/early-bound-1.rs
index 6b3b142014b..30843473def 100644
--- a/tests/ui/async-await/in-trait/early-bound-1.rs
+++ b/tests/ui/async-await/in-trait/early-bound-1.rs
@@ -1,5 +1,7 @@
 // check-pass
 // edition:2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![allow(incomplete_features)]
diff --git a/tests/ui/async-await/in-trait/early-bound-2.rs b/tests/ui/async-await/in-trait/early-bound-2.rs
index 270443229b0..1c5a68c2a5a 100644
--- a/tests/ui/async-await/in-trait/early-bound-2.rs
+++ b/tests/ui/async-await/in-trait/early-bound-2.rs
@@ -1,5 +1,7 @@
 // check-pass
 // edition:2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![allow(incomplete_features)]
diff --git a/tests/ui/async-await/in-trait/fn-not-async-err2.stderr b/tests/ui/async-await/in-trait/fn-not-async-err2.current.stderr
similarity index 93%
rename from tests/ui/async-await/in-trait/fn-not-async-err2.stderr
rename to tests/ui/async-await/in-trait/fn-not-async-err2.current.stderr
index 37d9669c012..1a749514989 100644
--- a/tests/ui/async-await/in-trait/fn-not-async-err2.stderr
+++ b/tests/ui/async-await/in-trait/fn-not-async-err2.current.stderr
@@ -1,5 +1,5 @@
 error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in `impl` method return types
-  --> $DIR/fn-not-async-err2.rs:13:22
+  --> $DIR/fn-not-async-err2.rs:15:22
    |
 LL |     fn foo(&self) -> impl Future<Output = i32> {
    |                      ^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/async-await/in-trait/fn-not-async-err2.next.stderr b/tests/ui/async-await/in-trait/fn-not-async-err2.next.stderr
new file mode 100644
index 00000000000..1a749514989
--- /dev/null
+++ b/tests/ui/async-await/in-trait/fn-not-async-err2.next.stderr
@@ -0,0 +1,12 @@
+error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in `impl` method return types
+  --> $DIR/fn-not-async-err2.rs:15:22
+   |
+LL |     fn foo(&self) -> impl Future<Output = i32> {
+   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
+   = help: add `#![feature(return_position_impl_trait_in_trait)]` to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.
diff --git a/tests/ui/async-await/in-trait/fn-not-async-err2.rs b/tests/ui/async-await/in-trait/fn-not-async-err2.rs
index 78017429f73..5fdb7296aaf 100644
--- a/tests/ui/async-await/in-trait/fn-not-async-err2.rs
+++ b/tests/ui/async-await/in-trait/fn-not-async-err2.rs
@@ -1,4 +1,6 @@
 // edition: 2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![allow(incomplete_features)]
diff --git a/tests/ui/async-await/in-trait/implied-bounds.rs b/tests/ui/async-await/in-trait/implied-bounds.rs
index 52bceb3cc5c..45ada1d84c3 100644
--- a/tests/ui/async-await/in-trait/implied-bounds.rs
+++ b/tests/ui/async-await/in-trait/implied-bounds.rs
@@ -1,5 +1,7 @@
 // check-pass
 // edition: 2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![allow(incomplete_features)]
diff --git a/tests/ui/async-await/in-trait/issue-102138.rs b/tests/ui/async-await/in-trait/issue-102138.rs
index f61b34ed99e..ced30b7e4e4 100644
--- a/tests/ui/async-await/in-trait/issue-102138.rs
+++ b/tests/ui/async-await/in-trait/issue-102138.rs
@@ -1,5 +1,7 @@
 // check-pass
 // edition:2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![allow(incomplete_features)]
diff --git a/tests/ui/async-await/in-trait/issue-102219.rs b/tests/ui/async-await/in-trait/issue-102219.rs
index 9a35f6515cb..f3fdfa3459a 100644
--- a/tests/ui/async-await/in-trait/issue-102219.rs
+++ b/tests/ui/async-await/in-trait/issue-102219.rs
@@ -1,6 +1,8 @@
 // compile-flags:--crate-type=lib
 // edition:2021
 // check-pass
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(async_fn_in_trait)]
 #![allow(incomplete_features)]
diff --git a/tests/ui/impl-trait/in-trait/deep-match-works.rs b/tests/ui/impl-trait/in-trait/deep-match-works.rs
index 772da845ee1..5c9d2e356fc 100644
--- a/tests/ui/impl-trait/in-trait/deep-match-works.rs
+++ b/tests/ui/impl-trait/in-trait/deep-match-works.rs
@@ -1,4 +1,6 @@
 // check-pass
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(return_position_impl_trait_in_trait)]
 #![allow(incomplete_features)]
@@ -10,7 +12,9 @@ trait Foo {
 }
 
 impl Foo for () {
-    fn bar() -> Wrapper<i32> { Wrapper(0) }
+    fn bar() -> Wrapper<i32> {
+        Wrapper(0)
+    }
 }
 
 fn main() {}
diff --git a/tests/ui/impl-trait/in-trait/deep-match.stderr b/tests/ui/impl-trait/in-trait/deep-match.current.stderr
similarity index 86%
rename from tests/ui/impl-trait/in-trait/deep-match.stderr
rename to tests/ui/impl-trait/in-trait/deep-match.current.stderr
index 3eba419c0a3..400db20c79c 100644
--- a/tests/ui/impl-trait/in-trait/deep-match.stderr
+++ b/tests/ui/impl-trait/in-trait/deep-match.current.stderr
@@ -1,7 +1,7 @@
 error[E0053]: method `bar` has an incompatible return type for trait
-  --> $DIR/deep-match.rs:11:17
+  --> $DIR/deep-match.rs:14:17
    |
-LL |     fn bar() -> i32 { 0 }
+LL |     fn bar() -> i32 {
    |                 ^^^
    |                 |
    |                 expected `Wrapper<_>`, found `i32`
diff --git a/tests/ui/impl-trait/in-trait/deep-match.next.stderr b/tests/ui/impl-trait/in-trait/deep-match.next.stderr
new file mode 100644
index 00000000000..400db20c79c
--- /dev/null
+++ b/tests/ui/impl-trait/in-trait/deep-match.next.stderr
@@ -0,0 +1,15 @@
+error[E0053]: method `bar` has an incompatible return type for trait
+  --> $DIR/deep-match.rs:14:17
+   |
+LL |     fn bar() -> i32 {
+   |                 ^^^
+   |                 |
+   |                 expected `Wrapper<_>`, found `i32`
+   |                 return type in trait
+   |
+   = note: expected struct `Wrapper<_>`
+                found type `i32`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0053`.
diff --git a/tests/ui/impl-trait/in-trait/deep-match.rs b/tests/ui/impl-trait/in-trait/deep-match.rs
index a6385147c3a..413d054e148 100644
--- a/tests/ui/impl-trait/in-trait/deep-match.rs
+++ b/tests/ui/impl-trait/in-trait/deep-match.rs
@@ -1,3 +1,6 @@
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
+
 #![feature(return_position_impl_trait_in_trait)]
 #![allow(incomplete_features)]
 
@@ -8,8 +11,10 @@ trait Foo {
 }
 
 impl Foo for () {
-    fn bar() -> i32 { 0 }
-    //~^ ERROR method `bar` has an incompatible return type for trait
+    fn bar() -> i32 {
+        //~^ ERROR method `bar` has an incompatible return type for trait
+        0
+    }
 }
 
 fn main() {}
diff --git a/tests/ui/impl-trait/in-trait/default-method-binder-shifting.stderr b/tests/ui/impl-trait/in-trait/default-method-binder-shifting.current.stderr
similarity index 89%
rename from tests/ui/impl-trait/in-trait/default-method-binder-shifting.stderr
rename to tests/ui/impl-trait/in-trait/default-method-binder-shifting.current.stderr
index 7c7ebcdb7e7..a0c0589b9a1 100644
--- a/tests/ui/impl-trait/in-trait/default-method-binder-shifting.stderr
+++ b/tests/ui/impl-trait/in-trait/default-method-binder-shifting.current.stderr
@@ -1,5 +1,5 @@
 warning: the feature `return_position_impl_trait_in_trait` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/default-method-binder-shifting.rs:3:12
+  --> $DIR/default-method-binder-shifting.rs:5:12
    |
 LL | #![feature(return_position_impl_trait_in_trait)]
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/impl-trait/in-trait/default-method-binder-shifting.next.stderr b/tests/ui/impl-trait/in-trait/default-method-binder-shifting.next.stderr
new file mode 100644
index 00000000000..a0c0589b9a1
--- /dev/null
+++ b/tests/ui/impl-trait/in-trait/default-method-binder-shifting.next.stderr
@@ -0,0 +1,11 @@
+warning: the feature `return_position_impl_trait_in_trait` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/default-method-binder-shifting.rs:5:12
+   |
+LL | #![feature(return_position_impl_trait_in_trait)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/impl-trait/in-trait/default-method-binder-shifting.rs b/tests/ui/impl-trait/in-trait/default-method-binder-shifting.rs
index 5cf90c5d93c..75b0ec93984 100644
--- a/tests/ui/impl-trait/in-trait/default-method-binder-shifting.rs
+++ b/tests/ui/impl-trait/in-trait/default-method-binder-shifting.rs
@@ -1,4 +1,6 @@
 // check-pass
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(return_position_impl_trait_in_trait)]
 //~^ WARN the feature `return_position_impl_trait_in_trait` is incomplete
diff --git a/tests/ui/impl-trait/in-trait/encode.rs b/tests/ui/impl-trait/in-trait/encode.rs
index efb9f6498ba..98aaf4a6553 100644
--- a/tests/ui/impl-trait/in-trait/encode.rs
+++ b/tests/ui/impl-trait/in-trait/encode.rs
@@ -1,5 +1,7 @@
 // build-pass
 // compile-flags: --crate-type=lib
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(return_position_impl_trait_in_trait)]
 #![allow(incomplete_features)]
diff --git a/tests/ui/impl-trait/in-trait/new-lowering-strategy/simple-impl-trait.rs b/tests/ui/impl-trait/in-trait/new-lowering-strategy/simple-impl-trait.rs
deleted file mode 100644
index ae09d20f6f5..00000000000
--- a/tests/ui/impl-trait/in-trait/new-lowering-strategy/simple-impl-trait.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-// check-pass
-// compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
-
-#![feature(return_position_impl_trait_in_trait)]
-#![allow(incomplete_features)]
-
-trait Foo {
-    fn foo() -> impl Sized;
-}
-
-impl Foo for String {
-    fn foo() -> i32 {
-        22
-    }
-}
-
-fn main() {}
diff --git a/tests/ui/impl-trait/in-trait/new-lowering-strategy/simple-trait.rs b/tests/ui/impl-trait/in-trait/new-lowering-strategy/simple-trait.rs
deleted file mode 100644
index dfce973d770..00000000000
--- a/tests/ui/impl-trait/in-trait/new-lowering-strategy/simple-trait.rs
+++ /dev/null
@@ -1,11 +0,0 @@
-// check-pass
-// compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
-
-#![feature(return_position_impl_trait_in_trait)]
-#![allow(incomplete_features)]
-
-trait Foo {
-    fn foo() -> impl Sized;
-}
-
-fn main() {}
diff --git a/tests/ui/impl-trait/in-trait/opaque-in-impl-is-opaque.stderr b/tests/ui/impl-trait/in-trait/opaque-in-impl-is-opaque.current.stderr
similarity index 91%
rename from tests/ui/impl-trait/in-trait/opaque-in-impl-is-opaque.stderr
rename to tests/ui/impl-trait/in-trait/opaque-in-impl-is-opaque.current.stderr
index 15edda48340..a57653b2c9e 100644
--- a/tests/ui/impl-trait/in-trait/opaque-in-impl-is-opaque.stderr
+++ b/tests/ui/impl-trait/in-trait/opaque-in-impl-is-opaque.current.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/opaque-in-impl-is-opaque.rs:17:19
+  --> $DIR/opaque-in-impl-is-opaque.rs:20:19
    |
 LL |     fn bar(&self) -> impl Display {
    |                      ------------ the found opaque type
diff --git a/tests/ui/impl-trait/in-trait/opaque-in-impl-is-opaque.next.stderr b/tests/ui/impl-trait/in-trait/opaque-in-impl-is-opaque.next.stderr
new file mode 100644
index 00000000000..a57653b2c9e
--- /dev/null
+++ b/tests/ui/impl-trait/in-trait/opaque-in-impl-is-opaque.next.stderr
@@ -0,0 +1,17 @@
+error[E0308]: mismatched types
+  --> $DIR/opaque-in-impl-is-opaque.rs:20:19
+   |
+LL |     fn bar(&self) -> impl Display {
+   |                      ------------ the found opaque type
+...
+LL |     let x: &str = ().bar();
+   |            ----   ^^^^^^^^ expected `&str`, found opaque type
+   |            |
+   |            expected due to this
+   |
+   = note: expected reference `&str`
+            found opaque type `impl std::fmt::Display`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/impl-trait/in-trait/opaque-in-impl-is-opaque.rs b/tests/ui/impl-trait/in-trait/opaque-in-impl-is-opaque.rs
index 3ac264e8eba..c07ece15a83 100644
--- a/tests/ui/impl-trait/in-trait/opaque-in-impl-is-opaque.rs
+++ b/tests/ui/impl-trait/in-trait/opaque-in-impl-is-opaque.rs
@@ -1,3 +1,6 @@
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
+
 #![feature(return_position_impl_trait_in_trait)]
 #![allow(incomplete_features)]
 
diff --git a/tests/ui/impl-trait/in-trait/reveal.rs b/tests/ui/impl-trait/in-trait/reveal.rs
index d6ede1cc495..1f42ec744db 100644
--- a/tests/ui/impl-trait/in-trait/reveal.rs
+++ b/tests/ui/impl-trait/in-trait/reveal.rs
@@ -1,4 +1,6 @@
 // check-pass
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(return_position_impl_trait_in_trait)]
 #![allow(incomplete_features)]
diff --git a/tests/ui/impl-trait/in-trait/signature-mismatch.stderr b/tests/ui/impl-trait/in-trait/signature-mismatch.current.stderr
similarity index 96%
rename from tests/ui/impl-trait/in-trait/signature-mismatch.stderr
rename to tests/ui/impl-trait/in-trait/signature-mismatch.current.stderr
index c4fcaabe446..eba270af7f0 100644
--- a/tests/ui/impl-trait/in-trait/signature-mismatch.stderr
+++ b/tests/ui/impl-trait/in-trait/signature-mismatch.current.stderr
@@ -1,5 +1,5 @@
 error: `impl` item signature doesn't match `trait` item signature
-  --> $DIR/signature-mismatch.rs:15:5
+  --> $DIR/signature-mismatch.rs:17:5
    |
 LL |     fn async_fn(&self, buff: &[u8]) -> impl Future<Output = Vec<u8>>;
    |     ----------------------------------------------------------------- expected `fn(&'1 Struct, &'2 [u8]) -> impl Future<Output = Vec<u8>> + '3`
diff --git a/tests/ui/impl-trait/in-trait/signature-mismatch.next.stderr b/tests/ui/impl-trait/in-trait/signature-mismatch.next.stderr
new file mode 100644
index 00000000000..eba270af7f0
--- /dev/null
+++ b/tests/ui/impl-trait/in-trait/signature-mismatch.next.stderr
@@ -0,0 +1,16 @@
+error: `impl` item signature doesn't match `trait` item signature
+  --> $DIR/signature-mismatch.rs:17:5
+   |
+LL |     fn async_fn(&self, buff: &[u8]) -> impl Future<Output = Vec<u8>>;
+   |     ----------------------------------------------------------------- expected `fn(&'1 Struct, &'2 [u8]) -> impl Future<Output = Vec<u8>> + '3`
+...
+LL |     fn async_fn<'a>(&self, buff: &'a [u8]) -> impl Future<Output = Vec<u8>> + 'a {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ found `fn(&'1 Struct, &'2 [u8]) -> impl Future<Output = Vec<u8>> + '2`
+   |
+   = note: expected signature `fn(&'1 Struct, &'2 [u8]) -> impl Future<Output = Vec<u8>> + '3`
+              found signature `fn(&'1 Struct, &'2 [u8]) -> impl Future<Output = Vec<u8>> + '2`
+   = help: the lifetime requirements from the `impl` do not correspond to the requirements in the `trait`
+   = help: verify the lifetime relationships in the `trait` and `impl` between the `self` argument, the other inputs and its output
+
+error: aborting due to previous error
+
diff --git a/tests/ui/impl-trait/in-trait/signature-mismatch.rs b/tests/ui/impl-trait/in-trait/signature-mismatch.rs
index 90682631aa0..38c902a97a9 100644
--- a/tests/ui/impl-trait/in-trait/signature-mismatch.rs
+++ b/tests/ui/impl-trait/in-trait/signature-mismatch.rs
@@ -1,4 +1,6 @@
 // edition:2021
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(return_position_impl_trait_in_trait)]
 #![allow(incomplete_features)]
diff --git a/tests/ui/impl-trait/in-trait/specialization-substs-remap.rs b/tests/ui/impl-trait/in-trait/specialization-substs-remap.rs
index c9ee877db8e..dbc5d38f192 100644
--- a/tests/ui/impl-trait/in-trait/specialization-substs-remap.rs
+++ b/tests/ui/impl-trait/in-trait/specialization-substs-remap.rs
@@ -1,4 +1,6 @@
 // check-pass
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(specialization)]
 #![feature(return_position_impl_trait_in_trait)]
diff --git a/tests/ui/impl-trait/in-trait/success.rs b/tests/ui/impl-trait/in-trait/success.rs
index 4cbe682b46f..0e69e0490c7 100644
--- a/tests/ui/impl-trait/in-trait/success.rs
+++ b/tests/ui/impl-trait/in-trait/success.rs
@@ -1,4 +1,6 @@
 // check-pass
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 #![feature(return_position_impl_trait_in_trait)]
 #![allow(incomplete_features)]