--- /dev/null
+error[E0276]: impl has stricter requirements than trait
+ --> $DIR/region-extra.rs:22:5
+ |
+18 | fn foo();
+ | --------- definition of `foo` from trait
+...
+22 | fn foo() where 'a: 'b { }
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^ impl has extra requirement `'a: 'b`
+
+error: aborting due to previous error
+