diff --git a/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/typecheck/tc-subst.rkt b/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/typecheck/tc-subst.rkt
index 8eb94373..456ca52d 100644
--- a/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/typecheck/tc-subst.rkt
+++ b/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/typecheck/tc-subst.rkt
@@ -61,11 +61,13 @@
 ;; This is essentially ψ+|ψ- [o/x] from the paper
 (define/cond-contract (subst-filter-set fs k o polarity [t Univ])
   (->* ((or/c FilterSet? NoFilter?) name-ref/c Object? boolean?) (Type/c) FilterSet?)
+  (define extra-filter (-filter t k))
   (define (add-extra-filter f)
-    (define f* (-and (-filter t k) f))
-    (match f*
-      [(Bot:) f*]
-      [_ f]))
+    (define f* (-and f extra-filter))
+    (cond
+      [(filter-equal? f* extra-filter) -top]
+      [(Bot? f*) -bot]
+      [else f]))
   (match fs
     [(FilterSet: f+ f-)
      (-FS (subst-filter (add-extra-filter f+) k o polarity)
diff --git a/pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/unit-tests/typecheck-tests.rkt b/pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/unit-tests/typecheck-tests.rkt
index f6bde25e..2e2230f8 100644
--- a/pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/unit-tests/typecheck-tests.rkt
+++ b/pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/unit-tests/typecheck-tests.rkt
@@ -573,7 +573,7 @@
 
         [tc-e/t (let ([x 1]) x) -One]
         [tc-e (let ([x 1]) (boolean? x)) #:ret (ret -Boolean -false-filter)]
-        [tc-e (boolean? number?) #:ret (ret -Boolean (-FS -bot (-not-filter -Boolean #'number?)))]
+        [tc-e (boolean? number?) #:ret (ret -Boolean -false-filter)]
 
         [tc-e (let: ([x : (Option Number) #f]) x) (t:Un -Number (-val #f))]
         [tc-e (let: ([x : Any 12]) (not (not x))) -Boolean]
@@ -917,7 +917,7 @@
           #:ret (ret -Number)]
         [tc-err (call-with-values 5
                                   (lambda: ([x : Number] [y : Number]) (+ x y)))
-          #:ret (ret -Number -bot-filter)]
+          #:ret (ret -Number)]
         [tc-err (call-with-values (lambda () (values 2))
                                   5)]
         [tc-err (call-with-values (lambda () (values 2 1))
@@ -1360,7 +1360,7 @@
         ;(tc-e (false? #t) #:ret (ret -Boolean -false-filter))
 
 
-        (tc-e (boolean? true) #:ret (ret -Boolean (-FS (-filter -Boolean #'true) -bot)))
+        (tc-e (boolean? true) #:ret (ret -Boolean -true-filter))
         (tc-e (boolean? 6) #:ret (ret -Boolean -false-filter))
         (tc-e (immutable? (cons 3 4)) -Boolean)
 
@@ -1533,12 +1533,12 @@
 
         (tc-e (namespace-anchor? 3) #:ret (ret -Boolean -false-filter))
         (tc-e/t (lambda: ((x : Namespace-Anchor)) (namespace-anchor? x))
-                (t:-> -Namespace-Anchor -Boolean : (-FS (-filter -Namespace-Anchor 0) -bot)))
+                (t:-> -Namespace-Anchor -Boolean : -true-filter))
 
 
         (tc-e (variable-reference? 3) #:ret (ret -Boolean -false-filter))
         (tc-e/t (lambda: ((x : Variable-Reference)) (variable-reference? x))
-                (t:-> -Variable-Reference  -Boolean : (-FS (-filter -Variable-Reference 0) -bot)))
+                (t:-> -Variable-Reference  -Boolean : -true-filter))
 
         (tc-e (system-type 'os) (one-of/c 'unix 'windows 'macosx))
         (tc-e (system-type 'gc) (one-of/c 'cgc '3m))