1 files changed, 4 insertions, 0 deletions

diff --git a/src/test/ui/issues/issue-42312.stderr b/tests/ui/issues/issue-42312.stderr
index 6fe151622..3ca6a2957 100644
--- a/src/test/ui/issues/issue-42312.stderr
+++ b/tests/ui/issues/issue-42312.stderr
@@ -23,6 +23,10 @@ LL | pub fn f(_: dyn ToString) {}
    |
    = help: the trait `Sized` is not implemented for `(dyn ToString + 'static)`
    = help: unsized fn params are gated as an unstable feature
+help: you can use `impl Trait` as the argument type
+   |
+LL | pub fn f(_: impl ToString) {}
+   |             ~~~~
 help: function arguments must have a statically known size, borrowed types always have a known size
    |
 LL | pub fn f(_: &dyn ToString) {}