diff --git a/collects/setup/private/omitted-paths.ss b/collects/setup/private/omitted-paths.ss
index 2ff28474a2..6862fff231 100644
--- a/collects/setup/private/omitted-paths.ss
+++ b/collects/setup/private/omitted-paths.ss
@@ -42,9 +42,10 @@
                  (let ([x (read)])
                    (if (eof-object? x)
                      (reverse r)
-                     (let* ([x (and (list? x) (= 7 (length x)) (list-ref x 4))]
-                            [x (and (bytes? x) (simplify-path (bytes->path x)))])
-                       (loop (if x (cons x r) r)))))))))))))
+                     (let ([x (and (list? x) (= 7 (length x)) (list-ref x 4))])
+                       (loop (if (bytes? x)
+                               (cons (simplify-path (bytes->path x)) r)
+                               r)))))))))))))
 
 ;; if `x' has `y' as a prefix, return the tail,
 ;; eg (relative-from '(1 2 3 4) '(1 2)) => '(3 4)
@@ -55,7 +56,7 @@
         [else #f]))
 
 (define-syntax-rule (with-memo t x expr)
-  (hash-ref t x (lambda () (let ([r expr]) (hash-set! t x r) r))))
+  (hash-ref! t x (lambda () expr)))
 
 (define ((implicit-omit? omit-doc?) path)
   (let ([str (path-element->string path)])
@@ -109,7 +110,7 @@
          [r (ormap (lambda (root+table)
                      (let ([r (relative-from dir* (car root+table))])
                        (and r (cons (reverse r) root+table))))
-                 roots)]
+                   roots)]
          [r (and r (apply accumulate-omitted r))])
     (unless r
       (error 'omitted-paths