diff --git a/collects/typed-scheme/optimizer/logging.rkt b/collects/typed-scheme/optimizer/logging.rkt
index 06f26eb1..e8e7b29a 100644
--- a/collects/typed-scheme/optimizer/logging.rkt
+++ b/collects/typed-scheme/optimizer/logging.rkt
@@ -214,7 +214,7 @@
   (define logger (current-logger))
   (add-missed-opts-to-log)
   (for ([x (sort-log)])
-    (log-message logger 'warning
+    (log-message logger 'debug
                  (format-log-entry x)
                  (cons optimization-log-key x))))
 
@@ -232,7 +232,7 @@
 ;; only intercepts TR log messages
 (define (with-intercepted-tr-logging interceptor thunk)
   (with-intercepted-logging
-   #:level 'warning
+   #:level 'debug
    (lambda (l) ;; look only for optimizer messages
      (when (log-message-from-tr-opt? l)
        (interceptor l)))
diff --git a/collects/typed-scheme/scribblings/guide/optimization.scrbl b/collects/typed-scheme/scribblings/guide/optimization.scrbl
index bcf01769..5a492363 100644
--- a/collects/typed-scheme/scribblings/guide/optimization.scrbl
+++ b/collects/typed-scheme/scribblings/guide/optimization.scrbl
@@ -181,8 +181,8 @@ can as a starting point for performance debugging.
 Similar information (albeit without in-depth explanations or advice) is
 available from the command line. When compiling a Typed Racket program, setting
 the racket @seclink[#:doc '(lib "scribblings/reference/reference.scrbl")
-"logging"]{logging} facilities to the @racket['warning] level causes Typed
+"logging"]{logging} facilities to the @racket['debug] level causes Typed
 Racket to display performance debugging information. Setting the Racket logging
 level can be done on the command line with the @racket[-W] flag:
 
-@commandline{racket -W warning my-typed-program.rkt}
+@commandline{racket -W debug my-typed-program.rkt}