diff --git a/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature.nll.stderr b/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature.nll.stderr
new file mode 100644
index 000000000000..f11c978aabf5
--- /dev/null
+++ b/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature.nll.stderr
@@ -0,0 +1,98 @@
+error[E0261]: use of undeclared lifetime name `'a`
+  --> $DIR/missing-lifetimes-in-signature.rs:37:11
+   |
+LL | fn baz<G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_
+   |        -  ^^ undeclared lifetime
+   |        |
+   |        help: consider introducing lifetime `'a` here: `'a,`
+
+error: lifetime may not live long enough
+  --> $DIR/missing-lifetimes-in-signature.rs:15:37
+   |
+LL | fn foo<G, T>(g: G, dest: &mut T) -> impl FnOnce()
+   |                          -          ^^^^^^^^^^^^^ opaque type requires that `'1` must outlive `'static`
+   |                          |
+   |                          let's call the lifetime of this reference `'1`
+   |
+help: to allow this `impl Trait` to capture borrowed data with lifetime `'1`, add `'_` as a bound
+   |
+LL | fn foo<G, T>(g: G, dest: &mut T) -> impl FnOnce() + '_
+   |                                     ^^^^^^^^^^^^^^^^^^
+
+error[E0311]: the parameter type `G` may not live long enough
+  --> $DIR/missing-lifetimes-in-signature.rs:25:37
+   |
+LL | fn bar<G, T>(g: G, dest: &mut T) -> impl FnOnce() + '_
+   |                                     ^^^^^^^^^^^^^^^^^^
+   |
+note: the parameter type `G` must be valid for the anonymous lifetime #1 defined on the function body at 25:1...
+  --> $DIR/missing-lifetimes-in-signature.rs:25:1
+   |
+LL | / fn bar<G, T>(g: G, dest: &mut T) -> impl FnOnce() + '_
+LL | |
+LL | | where
+LL | |     G: Get<T>
+...  |
+LL | |     }
+LL | | }
+   | |_^
+
+error[E0311]: the parameter type `G` may not live long enough
+  --> $DIR/missing-lifetimes-in-signature.rs:47:45
+   |
+LL | fn qux<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_
+   |                                             ^^^^^^^^^^^^^^^^^^
+   |
+note: the parameter type `G` must be valid for the anonymous lifetime #1 defined on the function body at 47:1...
+  --> $DIR/missing-lifetimes-in-signature.rs:47:1
+   |
+LL | / fn qux<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_
+LL | |
+LL | | where
+LL | |     G: Get<T>
+...  |
+LL | |     }
+LL | | }
+   | |_^
+
+error[E0311]: the parameter type `G` may not live long enough
+  --> $DIR/missing-lifetimes-in-signature.rs:58:45
+   |
+LL | fn bat<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_ + 'a
+   |                                             ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: the parameter type `G` must be valid for the anonymous lifetime #1 defined on the function body at 58:1...
+  --> $DIR/missing-lifetimes-in-signature.rs:58:1
+   |
+LL | / fn bat<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_ + 'a
+LL | |
+LL | | where
+LL | |     G: Get<T>
+...  |
+LL | |     }
+LL | | }
+   | |_^
+
+error[E0621]: explicit lifetime required in the type of `dest`
+  --> $DIR/missing-lifetimes-in-signature.rs:63:5
+   |
+LL |   fn bat<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_ + 'a
+   |                                    ------ help: add explicit lifetime `'a` to the type of `dest`: `&'a mut T`
+...
+LL | /     move || {
+LL | |         *dest = g.get();
+LL | |     }
+   | |_____^ lifetime `'a` required
+
+error[E0309]: the parameter type `G` may not live long enough
+  --> $DIR/missing-lifetimes-in-signature.rs:69:44
+   |
+LL | fn bak<'a, G, T>(g: G, dest: &'a mut T) -> impl FnOnce() + 'a
+   |                                            ^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider adding an explicit lifetime bound `G: 'a`...
+
+error: aborting due to 7 previous errors
+
+Some errors have detailed explanations: E0261, E0309, E0621.
+For more information about an error, try `rustc --explain E0261`.
diff --git a/src/test/ui/underscore-lifetime/dyn-trait-underscore.nll.stderr b/src/test/ui/underscore-lifetime/dyn-trait-underscore.nll.stderr
deleted file mode 100644
index a1f6c5386ae4..000000000000
--- a/src/test/ui/underscore-lifetime/dyn-trait-underscore.nll.stderr
+++ /dev/null
@@ -1,12 +0,0 @@
-error[E0621]: explicit lifetime required in the type of `items`
-  --> $DIR/dyn-trait-underscore.rs:8:5
-   |
-LL | fn a<T>(items: &[T]) -> Box<dyn Iterator<Item=&T>> {
-   |                ---- help: add explicit lifetime `'static` to the type of `items`: `&'static [T]`
-LL |     //                      ^^^^^^^^^^^^^^^^^^^^^ bound *here* defaults to `'static`
-LL |     Box::new(items.iter())
-   |     ^^^^^^^^^^^^^^^^^^^^^^ lifetime `'static` required
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0621`.