diff --git a/src/test/ui/issue-13033.stderr b/src/test/ui/issue-13033.stderr
index 2db3cb80a819e..f06d7360d85b0 100644
--- a/src/test/ui/issue-13033.stderr
+++ b/src/test/ui/issue-13033.stderr
@@ -9,6 +9,10 @@ LL |     fn bar(&mut self, other: &Foo) {}
    |
    = note: expected type `fn(&mut Baz, &mut dyn Foo)`
               found type `fn(&mut Baz, &dyn Foo)`
+help: consider change the type to match the mutability in trait
+   |
+LL |     fn bar(&mut self, other: &mut Foo) {}
+   |                              ^^^^^^^^
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/mismatched_types/E0053.stderr b/src/test/ui/mismatched_types/E0053.stderr
index 1b16694bf2c4d..f707a600f29e3 100644
--- a/src/test/ui/mismatched_types/E0053.stderr
+++ b/src/test/ui/mismatched_types/E0053.stderr
@@ -21,6 +21,10 @@ LL |     fn bar(&mut self) { }
    |
    = note: expected type `fn(&Bar)`
               found type `fn(&mut Bar)`
+help: consider change the type to match the mutability in trait
+   |
+LL |     fn bar(&self) { }
+   |            ^^^^^
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/mismatched_types/trait-impl-fn-incompatibility.stderr b/src/test/ui/mismatched_types/trait-impl-fn-incompatibility.stderr
index 28b16641e4dd5..631af21cac5ca 100644
--- a/src/test/ui/mismatched_types/trait-impl-fn-incompatibility.stderr
+++ b/src/test/ui/mismatched_types/trait-impl-fn-incompatibility.stderr
@@ -21,6 +21,10 @@ LL |     fn bar(&mut self, bar: &Bar) { } //~ ERROR incompatible type
    |
    = note: expected type `fn(&mut Bar, &mut Bar)`
               found type `fn(&mut Bar, &Bar)`
+help: consider change the type to match the mutability in trait
+   |
+LL |     fn bar(&mut self, bar: &mut Bar) { } //~ ERROR incompatible type
+   |                            ^^^^^^^^
 
 error: aborting due to 2 previous errors