diff --git a/collects/typed-racket/optimizer/fixnum.rkt b/collects/typed-racket/optimizer/fixnum.rkt
index 9c862c19..0bfa01dd 100644
--- a/collects/typed-racket/optimizer/fixnum.rkt
+++ b/collects/typed-racket/optimizer/fixnum.rkt
@@ -84,7 +84,7 @@
 (define (log-fixnum-missed-opt stx)
   (log-missed-optimization
    "out of fixnum range"
-   "This expression has all fixnum arguments but is not guaranteed to itself return a fixnum. Therefore, it cannot be safely optimized. Constraining the arguments to be of Byte or Index types may help."
+   "This expression consists of all fixnum arguments but is not guaranteed to produce a fixnum. Therefore it cannot be safely optimized. Constraining the arguments to be of Byte or Index types may help."
    stx))
 
 ;; general-purpose safety check for fixnum opts
diff --git a/collects/typed-racket/optimizer/float.rkt b/collects/typed-racket/optimizer/float.rkt
index 61601432..49149030 100644
--- a/collects/typed-racket/optimizer/float.rkt
+++ b/collects/typed-racket/optimizer/float.rkt
@@ -80,10 +80,10 @@
   (log-missed-optimization
    "all args float-arg-expr, result not Float"
    (string-append
-    "This expression has a Real type. It would be better optimized if it had a Float type."
+    "This expression has a Real type. The optimizer could improve its performance if it had type Float."
     (if (null? irritants)
         ""
-        "To fix this, change the highlighted expression(s) to have Float type(s)."))
+        "To fix, change the highlighted expression(s) to have Float type(s)."))
    stx irritants))
 
 (define float-opt-msg "Float arithmetic specialization.")