diff --git a/tests/ui/traits/custom-on-unimplemented-diagnostic.rs b/tests/ui/diagnostic_namespace/on_unimplemented/custom-on-unimplemented-diagnostic.rs
similarity index 100%
rename from tests/ui/traits/custom-on-unimplemented-diagnostic.rs
rename to tests/ui/diagnostic_namespace/on_unimplemented/custom-on-unimplemented-diagnostic.rs
diff --git a/tests/ui/traits/custom-on-unimplemented-diagnostic.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/custom-on-unimplemented-diagnostic.stderr
similarity index 100%
rename from tests/ui/traits/custom-on-unimplemented-diagnostic.stderr
rename to tests/ui/diagnostic_namespace/on_unimplemented/custom-on-unimplemented-diagnostic.stderr