diff --git a/collects/tests/typed-scheme/succeed/metrics.rkt b/collects/tests/typed-scheme/succeed/metrics.rkt
index 04a679fb..8839c7dd 100644
--- a/collects/tests/typed-scheme/succeed/metrics.rkt
+++ b/collects/tests/typed-scheme/succeed/metrics.rkt
@@ -84,11 +84,11 @@
            [table
             `((,a-hits ,b-hits)
               (,a-misses ,b-misses))]
-           [expected (lambda: ([i : Natural] [j : Natural])
+           [expected (lambda: ([i : Integer] [j : Integer])
                               (/ (* (row-total i table) (col-total j table)) total-subjects))])
       (exact->inexact 
        (table-sum 
-        (lambda: ([i : Natural] [j : Natural])
+        (lambda: ([i : Integer] [j : Integer])
                  (/ (sqr (- (expected i j) (table-ref i j table))) (expected i j)))
         table)))))
 
@@ -473,7 +473,7 @@
           (show result ))))
 
 ;; applies only to the combined metric [or more generally to listof-answer results]
-(pdefine: (a b c) (total [experiment-number : Natural] [result : (Result (Listof number) b c)]) : (Listof number)
+(pdefine: (a b c) (total [experiment-number : Integer] [result : (Result (Listof number) b c)]) : (Listof number)
           (define: (total/s [s : Table]) : number (apply + (list-ref (pivot s) experiment-number)))
           (list (total/s (result-seqA result)) (total/s (result-seqB result))))
 
@@ -491,7 +491,7 @@
             [(null? l) '()]
             [else
              (let ([n (length (car l))])
-               (build-list n (lambda: ([i : Natural]) (map (lambda: ([j : (Listof X)]) (list-ref j i)) l))))]))
+               (build-list n (lambda: ([i : Integer]) (map (lambda: ([j : (Listof X)]) (list-ref j i)) l))))]))
 
 (define: (sqr [x : Real]) : Real (* x x))
 (define: (variance [xs : (Listof Real)]): Real
@@ -499,13 +499,13 @@
     (/ (apply + (map (lambda: ([x : number]) (sqr (- x avg))) xs))
        (sub1 (length xs)))))
 
-(define: (table-ref [i : Natural] [j : Natural] [table : Table]): number
+(define: (table-ref [i : Integer] [j : Integer] [table : Table]): number
   (list-ref (list-ref table i) j))
-(define: (row-total [i : Natural] [table : Table]) : number
+(define: (row-total [i : Integer] [table : Table]) : number
   (apply + (list-ref table i)))
-(define: (col-total [j : Natural] [table : Table]) : number
+(define: (col-total [j : Integer] [table : Table]) : number
   (apply + (map (lambda: ([x : (Listof number)]) (list-ref x j)) table)))
-(define: (table-sum [f : (Natural Natural -> Real)] [table : Table]) : number
+(define: (table-sum [f : (Integer Integer -> Real)] [table : Table]) : number
   (let ([rows (length table)]
         [cols (length (car table))])
     (let loop ([i 0] [j 0] [#{sum : Real} 0])
diff --git a/collects/tests/typed-scheme/succeed/new-metrics.rkt b/collects/tests/typed-scheme/succeed/new-metrics.rkt
index 5513eda8..4635f79f 100644
--- a/collects/tests/typed-scheme/succeed/new-metrics.rkt
+++ b/collects/tests/typed-scheme/succeed/new-metrics.rkt
@@ -61,7 +61,7 @@
            [table
             `((,a-hits ,b-hits)
               (,a-misses ,b-misses))]
-           [expected (λ: ([i : Natural] [j : Natural])
+           [expected (λ: ([i : Integer] [j : Integer])
                          (/ (* (row-total i table) (col-total j table)) total-subjects))])
       (exact->inexact 
        (table-sum 
@@ -425,7 +425,7 @@
           (show result))))
 
 ;; applies only to the combined metric [or more generally to listof-answer results]
-(: total (All (b c) (Natural (result (Listof Number) b c) -> (Listof Number))))
+(: total (All (b c) (Integer (result (Listof Number) b c) -> (Listof Number))))
 (define (total experiment-number result)
   (: total/s (Table -> Number))
   (define (total/s s) (apply + (list-ref (pivot s) experiment-number)))
@@ -447,7 +447,7 @@
     [(null? l) '()]
     [else
      (let ([n (length (car l))])
-       (build-list n (λ: ([i : Natural]) (map (λ: ([j : (Listof X)]) (list-ref j i)) l))))]))
+       (build-list n (λ: ([i : Integer]) (map (λ: ([j : (Listof X)]) (list-ref j i)) l))))]))
 
 (: variance ((Listof Number) -> Number))
 (define (variance xs)
@@ -455,16 +455,16 @@
     (/ (apply + (map (λ: ([x : Number]) (sqr (- x avg))) xs))
        (sub1 (length xs)))))
 
-(: table-ref (Natural Natural Table -> Number))
+(: table-ref (Integer Integer Table -> Number))
 (define (table-ref i j table)
   (list-ref (list-ref table i) j))
-(: row-total (Natural Table -> Number))
+(: row-total (Integer Table -> Number))
 (define (row-total i table)
   (apply + (list-ref table i)))
-(: col-total (Natural Table -> Number))
+(: col-total (Integer Table -> Number))
 (define (col-total j table)
   (apply + (map (λ: ([x : (Listof Number)]) (list-ref x j)) table)))
-(: table-sum ((Natural Natural -> Number) Table -> Number))
+(: table-sum ((Integer Integer -> Number) Table -> Number))
 (define (table-sum f table)
   (let ([rows (length table)]
         [cols (length (car table))])
diff --git a/collects/tests/typed-scheme/unit-tests/typecheck-tests.rkt b/collects/tests/typed-scheme/unit-tests/typecheck-tests.rkt
index 406dc955..e03ec46d 100644
--- a/collects/tests/typed-scheme/unit-tests/typecheck-tests.rkt
+++ b/collects/tests/typed-scheme/unit-tests/typecheck-tests.rkt
@@ -154,10 +154,10 @@
         [tc-e (void) -Void]
         [tc-e (void 3 4) -Void]
         [tc-e (void #t #f '(1 2 3)) -Void]
-        [tc-e/t #(3 4 5) (make-HeterogenousVector (list -Nat -Nat -Nat))]
+        [tc-e/t #(3 4 5) (make-HeterogenousVector (list -Integer -Integer -Integer))]
         [tc-e/t '(2 3 4) (-lst* -PositiveFixnum -PositiveFixnum -PositiveFixnum)]
         [tc-e/t '(2 3 #t) (-lst* -PositiveFixnum -PositiveFixnum (-val #t))]
-        [tc-e/t #(2 3 #t) (make-HeterogenousVector (list -Nat -Nat (-val #t)))]
+        [tc-e/t #(2 3 #t) (make-HeterogenousVector (list -Integer -Integer (-val #t)))]
         [tc-e/t '(#t #f) (-lst* (-val #t) (-val #f))]
         [tc-e/t (plambda: (a) ([l : (Listof a)]) (car l))
                 (make-Poly '(a) (t:-> (make-Listof (-v a)) (-v a)))]
diff --git a/collects/typed-scheme/private/base-env-indexing-abs.rkt b/collects/typed-scheme/private/base-env-indexing-abs.rkt
index a2525f1d..c4c852d2 100644
--- a/collects/typed-scheme/private/base-env-indexing-abs.rkt
+++ b/collects/typed-scheme/private/base-env-indexing-abs.rkt
@@ -137,7 +137,7 @@
    [unsafe-vector-set! (-poly (a) (-> (-vec a) index-type a -Void))]
    [unsafe-vector*-set! (-poly (a) (-> (-vec a) index-type a -Void))]
    [vector-copy! (-poly (a) ((-vec a) index-type (-vec a) [index-type index-type] . ->opt . -Void))]
-   [make-vector (-poly (a) (cl-> [(index-type) (-vec (Un -Nat a))]
+   [make-vector (-poly (a) (cl-> [(index-type) (-vec (Un -Integer a))]
                                  [(index-type a) (-vec a)]))]
 
    [bytes-ref (-> -Bytes index-type -NonnegativeFixnum)]