diff --git a/typed-racket-lib/typed-racket/base-env/base-env-indexing-abs.rkt b/typed-racket-lib/typed-racket/base-env/base-env-indexing-abs.rkt
index 12fc07eb..da29cd09 100644
--- a/typed-racket-lib/typed-racket/base-env/base-env-indexing-abs.rkt
+++ b/typed-racket-lib/typed-racket/base-env/base-env-indexing-abs.rkt
@@ -311,11 +311,8 @@
    [integer->integer-bytes (-Integer index-type Univ [Univ -Bytes index-type] . ->opt . -Bytes)]
    [integer-bytes->integer
     (cl->*
-     ;; Any truthy value (not only #t) would work here.
-     ;; We can define a truthy type (without difference types (- Univ #f))
-     ;; by unioning everything (including StructTop and co).
-     ;; We should do this at some point.
-     (-Bytes (-val #t) [Univ index-type index-type] . ->opt . -Nat)
+     ;; Second argument is `signed?` --- if `#false` the result is a `-Nat`
+     (-Bytes (-val #f) [Univ index-type index-type] . ->opt . -Nat)
      (-Bytes Univ [Univ index-type index-type] . ->opt . -Integer))]
 
    [peek-char
diff --git a/typed-racket-test/unit-tests/typecheck-tests.rkt b/typed-racket-test/unit-tests/typecheck-tests.rkt
index 7991da67..182f6f0e 100644
--- a/typed-racket-test/unit-tests/typecheck-tests.rkt
+++ b/typed-racket-test/unit-tests/typecheck-tests.rkt
@@ -664,8 +664,8 @@
                     (when (boolean? x) #t))
               -Void]
 
-        [tc-e (integer-bytes->integer '#"abcd" #t) -Nat]
-        [tc-e (integer-bytes->integer '#"abcd" #f) -Int]
+        [tc-e (integer-bytes->integer '#"abcd" #t) -Int]
+        [tc-e (integer-bytes->integer '#"abcd" #f) -Nat]
 
         [tc-e/t (let: ([x : Any 3])
                     (if (list? x)