diff --git a/collects/tests/racket/benchmarks/shootout/typed/nbody-generic.rktl b/collects/tests/racket/benchmarks/shootout/typed/nbody-generic.rktl
index 25287c5d0a..f00fd9504a 100644
--- a/collects/tests/racket/benchmarks/shootout/typed/nbody-generic.rktl
+++ b/collects/tests/racket/benchmarks/shootout/typed/nbody-generic.rktl
@@ -76,8 +76,7 @@ Correct output N = 1000 is
 ;; -------------------------------
 (: offset-momentum ( -> Void))
 (define (offset-momentum)
-  (let: loop-i : Void ([i : (Listof body) *system*]
-                       [px : Float 0.0] [py : Float 0.0] [pz : Float 0.0])
+  (let loop-i ([i *system*] [px 0.0] [py 0.0] [pz 0.0])
     (if (null? i)
       (begin
         (set-body-vx! (car *system*) (/ (- px) +solar-mass+))
@@ -92,7 +91,7 @@ Correct output N = 1000 is
 ;; -------------------------------
 (: energy ( -> Float))
 (define (energy)
-  (let: loop-o : Float ([o : (Listof body) *system*] [e : Float 0.0])
+  (let loop-o ([o *system*] [e 0.0])
     (if (null? o)
       e
       (let* ([o1 (car o)]
diff --git a/collects/tests/racket/benchmarks/shootout/typed/nbody-vec-generic.rktl b/collects/tests/racket/benchmarks/shootout/typed/nbody-vec-generic.rktl
index 2347175320..a7844c0991 100644
--- a/collects/tests/racket/benchmarks/shootout/typed/nbody-vec-generic.rktl
+++ b/collects/tests/racket/benchmarks/shootout/typed/nbody-vec-generic.rktl
@@ -85,8 +85,7 @@ Correct output N = 1000 is
 ;; -------------------------------
 (: offset-momentum ( -> Void))
 (define (offset-momentum)
-  (let: loop-i : Void ([i : Natural 0]
-                       [px : Float 0.0] [py : Float 0.0] [pz : Float 0.0])
+  (let loop-i ([i 0] [px 0.0] [py 0.0] [pz 0.0])
     (if (= i *system-size*)
       (begin
         (set-body-vx! (vector-ref *system* 0) (/ (- px) +solar-mass+))
@@ -101,7 +100,7 @@ Correct output N = 1000 is
 ;; -------------------------------
 (: energy ( -> Float))
 (define (energy)
-  (let: loop-o : Float ([o : Natural 0] [e : Float 0.0])
+  (let loop-o ([o 0] [e 0.0])
     (if (= o *system-size*)
       e
       (let* ([o1 (vector-ref *system* o)]
diff --git a/collects/tests/racket/benchmarks/shootout/typed/nbody-vec-unsafe.rktl b/collects/tests/racket/benchmarks/shootout/typed/nbody-vec-unsafe.rktl
index c5679d68ff..a57e1ff568 100644
--- a/collects/tests/racket/benchmarks/shootout/typed/nbody-vec-unsafe.rktl
+++ b/collects/tests/racket/benchmarks/shootout/typed/nbody-vec-unsafe.rktl
@@ -90,8 +90,7 @@ Correct output N = 1000 is
 ;; -------------------------------
 (: offset-momentum ( -> Void))
 (define (offset-momentum)
-  (let: loop-i : Void ([i : Natural 0]
-                       [px : Float 0.0] [py : Float 0.0] [pz : Float 0.0])
+  (let loop-i ([i 0] [px 0.0] [py 0.0] [pz 0.0])
     (if (unsafe-fx= i *system-size*)
       (begin
         (set-body-vx! (unsafe-vector-ref *system* 0) (fl/ (fl- 0.0 px) +solar-mass+))
@@ -106,7 +105,7 @@ Correct output N = 1000 is
 ;; -------------------------------
 (: energy ( -> Float))
 (define (energy)
-  (let: loop-o : Float ([o : Natural 0] [e : Float 0.0])
+  (let loop-o ([o 0] [e 0.0])
     (if (unsafe-fx= o *system-size*)
       e
       (let* ([o1 (unsafe-vector-ref *system* o)]
diff --git a/collects/tests/racket/benchmarks/shootout/typed/nbody-vec.rktl b/collects/tests/racket/benchmarks/shootout/typed/nbody-vec.rktl
index f133e32f3b..fe78b7b436 100644
--- a/collects/tests/racket/benchmarks/shootout/typed/nbody-vec.rktl
+++ b/collects/tests/racket/benchmarks/shootout/typed/nbody-vec.rktl
@@ -85,8 +85,7 @@ Correct output N = 1000 is
 ;; -------------------------------
 (: offset-momentum ( -> Void))
 (define (offset-momentum)
-  (let: loop-i : Void ([i : Natural 0]
-                       [px : Float 0.0] [py : Float 0.0] [pz : Float 0.0])
+  (let loop-i ([i 0] [px 0.0] [py 0.0] [pz 0.0])
     (if (= i *system-size*)
       (begin
         (set-body-vx! (vector-ref *system* 0) (fl/ (fl- 0.0 px) +solar-mass+))
@@ -101,7 +100,7 @@ Correct output N = 1000 is
 ;; -------------------------------
 (: energy ( -> Float))
 (define (energy)
-  (let: loop-o : Float ([o : Natural 0] [e : Float 0.0])
+  (let loop-o ([o 0] [e 0.0])
     (if (= o *system-size*)
       e
       (let* ([o1 (vector-ref *system* o)]
diff --git a/collects/tests/racket/benchmarks/shootout/typed/nbody.rktl b/collects/tests/racket/benchmarks/shootout/typed/nbody.rktl
index 12caa20d20..9828756499 100644
--- a/collects/tests/racket/benchmarks/shootout/typed/nbody.rktl
+++ b/collects/tests/racket/benchmarks/shootout/typed/nbody.rktl
@@ -77,8 +77,7 @@ Correct output N = 1000 is
 ;; -------------------------------
 (: offset-momentum ( -> Void))
 (define (offset-momentum)
-  (let: loop-i : Void ([i : (Listof body) *system*]
-                       [px : Float 0.0] [py : Float 0.0] [pz : Float 0.0])
+  (let loop-i ([i *system*] [px 0.0] [py 0.0] [pz 0.0])
     (if (null? i)
       (begin
         (set-body-vx! (car *system*) (fl/ (fl- 0.0 px) +solar-mass+))
@@ -93,7 +92,7 @@ Correct output N = 1000 is
 ;; -------------------------------
 (: energy ( -> Float))
 (define (energy)
-  (let: loop-o : Float ([o : (Listof body) *system*] [e : Float 0.0])
+  (let loop-o ([o *system*] [e 0.0])
     (if (null? o)
       e
       (let* ([o1 (car o)]
diff --git a/collects/tests/racket/benchmarks/shootout/typed/spectralnorm-unsafe.rktl b/collects/tests/racket/benchmarks/shootout/typed/spectralnorm-unsafe.rktl
index 61a990ccb9..ec4bd015a6 100644
--- a/collects/tests/racket/benchmarks/shootout/typed/spectralnorm-unsafe.rktl
+++ b/collects/tests/racket/benchmarks/shootout/typed/spectralnorm-unsafe.rktl
@@ -45,8 +45,8 @@
 (define (MultiplyAv n v Av)
   (for ([i (in-range n)])
     (flvector-set! Av i 
-                   (for/fold: : Float ([r : Float 0.0])
-                       ([j : Natural (in-range n)])
+                   (for/fold ([r 0.0])
+                       ([j (in-range n)])
                      (fl+ r (fl* (A i j) (flvector-ref v j)))))))
 
 ;; multiply vector v by matrix A transposed
@@ -54,8 +54,8 @@
 (define (MultiplyAtv n v Atv)
   (for ([i (in-range n)])
     (flvector-set! Atv i
-                   (for/fold: : Float ([r : Float 0.0])
-                       ([j : Natural (in-range n)])
+                   (for/fold ([r 0.0])
+                       ([j (in-range n)])
                      (fl+ r (fl* (A j i) (flvector-ref v j)))))))
 
 ;; multiply vector v by matrix A and then by matrix A transposed 
diff --git a/collects/tests/racket/benchmarks/shootout/typed/spectralnorm.rktl b/collects/tests/racket/benchmarks/shootout/typed/spectralnorm.rktl
index 24d9830743..6d936ffaac 100644
--- a/collects/tests/racket/benchmarks/shootout/typed/spectralnorm.rktl
+++ b/collects/tests/racket/benchmarks/shootout/typed/spectralnorm.rktl
@@ -18,7 +18,7 @@
     
     ;; B=AtA         A multiplied by A transposed
     ;; v.Bv /(v.v)   eigenvalue of v
-    (let: loop : Float ([i : Natural 0][vBv : Float 0.0][vv : Float 0.0])
+    (let loop ([i 0][vBv 0.0][vv 0.0])
       (if (= i n)
           (flsqrt (fl/ vBv vv))
           (let ([vi (flvector-ref v i)])
@@ -38,8 +38,8 @@
 (define (MultiplyAv n v Av)
   (for: : Void ([i : Natural (in-range n)])
     (flvector-set! Av i 
-                   (for/fold: : Float ([r : Float 0.0])
-                       ([j : Natural (in-range n)])
+                   (for/fold ([r 0.0])
+                       ([j (in-range n)])
                      (fl+ r (fl* (A i j) (flvector-ref v j)))))))
 
 ;; multiply vector v by matrix A transposed
@@ -47,8 +47,8 @@
 (define (MultiplyAtv n v Atv)
   (for: : Void ([i : Natural (in-range n)])
     (flvector-set! Atv i
-                   (for/fold: : Float ([r : Float 0.0])
-                       ([j : Natural (in-range n)])
+                   (for/fold ([r 0.0])
+                       ([j (in-range n)])
                      (fl+ r (fl* (A j i) (flvector-ref v j)))))))
 
 ;; multiply vector v by matrix A and then by matrix A transposed
diff --git a/collects/typed-scheme/types/convenience.rkt b/collects/typed-scheme/types/convenience.rkt
index 2ba838be20..25869544f1 100644
--- a/collects/typed-scheme/types/convenience.rkt
+++ b/collects/typed-scheme/types/convenience.rkt
@@ -33,6 +33,7 @@
 	[(Value: 0) -Nat]
         [(? (lambda (t) (subtype t -Nat))) -Nat]
         [(? (lambda (t) (subtype t -Integer))) -Integer]
+        [(? (lambda (t) (subtype t -Flonum))) -Flonum]
         [(Mu: var (Union: (list (Value: '()) (Pair: _ (F: var))))) t*]
         [(Pair: t1 (Value: '())) (-lst t1)]
         [(MPair: t1 (Value: '())) (-mlst t1)]