diff --git a/crates/red_knot_python_semantic/src/types.rs b/crates/red_knot_python_semantic/src/types.rs
index 8c6e2e7c47..c6d0757f9e 100644
--- a/crates/red_knot_python_semantic/src/types.rs
+++ b/crates/red_knot_python_semantic/src/types.rs
@@ -475,7 +475,7 @@ impl<'db> Type<'db> {
             | Type::Todo
             | Type::Unbound
             | Type::Module(..)
-            | Type::Instance(..)
+            | Type::Instance(..) // TODO some instance types can be singleton types (EllipsisType, NotImplementedType)
             | Type::IntLiteral(..)
             | Type::StringLiteral(..)
             | Type::BytesLiteral(..)