diff --git a/collects/compiler/decompile.ss b/collects/compiler/decompile.ss
index 1448bb138d..e1e9ffaf88 100644
--- a/collects/compiler/decompile.ss
+++ b/collects/compiler/decompile.ss
@@ -75,7 +75,7 @@
                 (if (null? stx-ids) null '(#%stx-array))
                 lift-ids)
                (map (lambda (stx id)
-                      `(define ,id (decode-stx ,(stx-encoded stx))))
+                      `(define ,id (#%decode-syntax ,(stx-encoded stx))))
                     stxs stx-ids)))]
     [else (error 'decompile-prefix "huh?: ~e" a-prefix)]))
 
@@ -174,11 +174,14 @@
     [(struct assign (id rhs undef-ok?))
      `(set! ,(decompile-expr id globs stack)
             ,(decompile-expr rhs globs stack))]
-    [(struct localref (unbox? offset flags))
+    [(struct localref (unbox? offset clear?))
      (let ([id (list-ref/protect stack offset)])
-       (if unbox?
-           `(#%unbox ,id)
-           id))]
+       (let ([e (if unbox?
+                    `(#%unbox ,id)
+                    id)])
+         (if clear?
+             `(#%sfs-clear ,e)
+             e)))]
     [(struct lam (name flags num-params rest? closure-map max-let-depth body))
      (let ([vars (for/list ([i (in-range num-params)]) (gensym 'arg))]
            [rest-vars (if rest? (list (gensym 'rest)) null)])
@@ -240,8 +243,8 @@
                   (decompile-expr rand globs stack))
                 rands)))]
     [(struct apply-values (proc args-expr))
-     `(apply-values ,(decompile-expr proc globs stack) 
-                    ,(decompile-expr args-expr globs stack))]
+     `(#%apply-values ,(decompile-expr proc globs stack) 
+                      ,(decompile-expr args-expr globs stack))]
     [(struct sequence (exprs))
      `(begin ,@(for/list ([expr (in-list exprs)])
                  (decompile-expr expr globs stack)))]
@@ -254,7 +257,7 @@
           ,(decompile-expr val globs stack)
           ,(decompile-expr body globs stack))]
     [(struct closure (lam gen-id))
-     `(CLOSED ,gen-id ,(decompile-expr lam globs stack))]
+     `(#%closed ,gen-id ,(decompile-expr lam globs stack))]
     [(struct indirect (val))
      (if (closure? val)
          (closure-gen-id val)
diff --git a/collects/compiler/zo-parse.ss b/collects/compiler/zo-parse.ss
index 8007070022..a739445462 100644
--- a/collects/compiler/zo-parse.ss
+++ b/collects/compiler/zo-parse.ss
@@ -35,7 +35,7 @@
 (define-form-struct let-rec (procs body)) ; put `letrec'-bound closures into existing stack slots
 (define-form-struct boxenv (pos body)) ; box existing stack element
 
-(define-form-struct localref (unbox? offset flags)) ; access local via stack
+(define-form-struct localref (unbox? offset clear?)) ; access local via stack
 
 (define-form-struct toplevel (depth pos flags))  ; access binding via prefix array (which is on stack)
 (define-form-struct topsyntax (depth pos midpt)) ; access syntax object via prefix array (which is on stack)
@@ -408,6 +408,10 @@
          [reader (get-reader type)])
     (reader l)))
 
+(define (make-local unbox? pos flags)
+  (define SCHEME_LOCAL_CLEAR_ON_READ #x01)
+  (make-localref unbox? pos (positive? (bitwise-and flags SCHEME_LOCAL_CLEAR_ON_READ))))
+
 (define (a . << . b)
   (arithmetic-shift a b))
 
@@ -482,7 +486,7 @@
                   [flags (if (< p* 0)
                              (read-compact-number cp)
                              0)])
-             (make-localref #t p flags))]
+             (make-local #t p flags))]
           [(path)
            (let* ([p (bytes->path (read-compact-bytes cp (read-compact-number cp)))])
              (if (relative-path? p)
@@ -527,12 +531,12 @@
            (let ([c (read-compact-number cp)]
                  [unbox? (eq? cpt-tag 'local-unbox)])
              (if (negative? c)
-                 (make-localref unbox? (- (add1 c)) (read-compact-number cp))
-                 (make-localref unbox? c 0)))]
+                 (make-local unbox? (- (add1 c)) (read-compact-number cp))
+                 (make-local unbox? c 0)))]
           [(small-local)
-           (make-localref #f (- ch cpt-start) 0)]
+           (make-local #f (- ch cpt-start) 0)]
           [(small-local-unbox)
-           (make-localref #t (- ch cpt-start) 0)]
+           (make-local #t (- ch cpt-start) 0)]
           [(small-symbol)
            (let ([l (- ch cpt-start)])
              (string->symbol (read-compact-chars cp l)))]