1 files changed, 11 insertions, 0 deletions
diff --git a/src/test/ui/type/type-parameter-defaults-referencing-Self.rs b/src/test/ui/type/type-parameter-defaults-referencing-Self.rs
new file mode 100644
index 000000000..e5c81556e
--- /dev/null
+++ b/src/test/ui/type/type-parameter-defaults-referencing-Self.rs
@@ -0,0 +1,11 @@
+// Test a default that references `Self` which is then used in an object type.
+// Issue #18956.
+
+trait Foo<T=Self> {
+    fn method(&self);
+}
+
+fn foo(x: &dyn Foo) { }
+//~^ ERROR the type parameter `T` must be explicitly specified
+
+fn main() { }