diff --git a/src/librustc_typeck/check/closure.rs b/src/librustc_typeck/check/closure.rs
index 0f68b1597784..7e7e1018f977 100644
--- a/src/librustc_typeck/check/closure.rs
+++ b/src/librustc_typeck/check/closure.rs
@@ -32,7 +32,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         debug!("check_expr_closure(expr={:?},expected={:?})",
                expr,
                expected);
-        // FIXME: See if expected_kind here can impact generators
+        // FIXME: Should we adapt deduce_expectations_from_expected_type to work with
+        // generator traits? It looks like it's conservative to add support for this later.
 
         // It's always helpful for inference if we know the kind of
         // closure sooner rather than later, so first examine the expected