diff --git a/collects/tests/racket/benchmarks/shootout/lists.rkt b/collects/tests/racket/benchmarks/shootout/lists.rkt
index 9667daadc4..f2a735fe85 100644
--- a/collects/tests/racket/benchmarks/shootout/lists.rkt
+++ b/collects/tests/racket/benchmarks/shootout/lists.rkt
@@ -33,7 +33,7 @@
           (else           (mlength L1)))))
 
 (define (main args)
-  (let ((result #f))
+  (let ((result 0))
     (let loop ((counter (if (= (vector-length args) 0)
                             1
                             (string->number (vector-ref args 0)))))
diff --git a/collects/tests/racket/benchmarks/shootout/moments.rkt b/collects/tests/racket/benchmarks/shootout/moments.rkt
index 0d4355413d..7044cc342e 100644
--- a/collects/tests/racket/benchmarks/shootout/moments.rkt
+++ b/collects/tests/racket/benchmarks/shootout/moments.rkt
@@ -3,7 +3,8 @@
 #lang racket/base
 
 (require (only-in mzlib/list sort)
-         (only-in mzlib/string real->decimal-string))
+         (only-in mzlib/string real->decimal-string)
+         racket/flonum)
 
 (define (to-str n) (real->decimal-string n 6))
 
@@ -29,15 +30,15 @@
               (begin
                 (set! deviation (- (car nums) mean))
                 (set! average_deviation (+ average_deviation (abs deviation)))
-                (set! variance (+ variance (expt deviation 2.0)))
-                (set! skew (+ skew (expt deviation 3.0)))
+                (set! variance (+ variance (expt deviation 2)))
+                (set! skew (+ skew (expt deviation 3)))
                 (set! kurtosis (+ kurtosis (expt deviation 4)))
                 (loop (cdr nums)))
               #t))
 
         (set! average_deviation (/ average_deviation (exact->inexact n)))
         (set! variance (/ variance (- n 1)))
-        (set! standard_deviation (sqrt variance))
+        (set! standard_deviation (flsqrt variance))
 
         (cond ((> variance 0.0)
                (set! skew (/ skew (* n variance standard_deviation)))
diff --git a/collects/tests/racket/benchmarks/shootout/nbody.rkt b/collects/tests/racket/benchmarks/shootout/nbody.rkt
index 7e94db096c..619e43f8e4 100644
--- a/collects/tests/racket/benchmarks/shootout/nbody.rkt
+++ b/collects/tests/racket/benchmarks/shootout/nbody.rkt
@@ -26,7 +26,7 @@ Correct output N = 1000 is
 (define +pi+ 3.141592653589793)
 (define +days-per-year+ 365.24)
 
-(define +solar-mass+ (* 4 +pi+ +pi+))
+(define +solar-mass+ (* 4.0 +pi+ +pi+))
 
 (define +dt+ 0.01)