diff --git a/module/language/tree-il/optimize.scm b/module/language/tree-il/optimize.scm
index 3c3cb01ca..0567b0cfa 100644
--- a/module/language/tree-il/optimize.scm
+++ b/module/language/tree-il/optimize.scm
@@ -92,6 +92,15 @@ references to the new symbols."
               (vals    (map (cut loop <> mapping) vals))
               (body    (loop body mapping)))
          (make-letrec src in-order? names new vals body)))
+      (($ <fix> src names gensyms vals body)
+       ;; Likewise.
+       (let* ((new     (fresh-gensyms names))
+              (mapping (fold vhash-consq mapping gensyms new))
+              (vals    (map (cut loop <> mapping) vals))
+              (body    (loop body mapping)))
+         (make-fix src names new vals body)))
+      (($ <let-values> src exp body)
+       (make-let-values src (loop exp mapping) (loop body mapping)))
       (($ <const>)
        exp)
       (($ <void>)
@@ -102,6 +111,24 @@ references to the new symbols."
        exp)
       (($ <primitive-ref>)
        exp)
+      (($ <toplevel-set> src name exp)
+       (make-toplevel-set src name (loop exp mapping)))
+      (($ <toplevel-define> src name exp)
+       (make-toplevel-define src name (loop exp mapping)))
+      (($ <module-set> src mod name public? exp)
+       (make-module-set src mod name public? (loop exp mapping)))
+      (($ <dynlet> src fluids vals body)
+       (make-dynlet src
+                    (map (cut loop <> mapping) fluids)
+                    (map (cut loop <> mapping) vals)
+                    (loop body mapping)))
+      (($ <dynwind> src winder body unwinder)
+       (make-dynwind src
+                     (loop winder mapping)
+                     (loop body mapping)
+                     (loop unwinder mapping)))
+      (($ <dynref> src fluid)
+       (make-dynref src (loop fluid mapping)))
       (($ <conditional> src condition subsequent alternate)
        (make-conditional src
                          (loop condition mapping)