diff --git a/scribblings/cs019.scrbl b/scribblings/cs019.scrbl
index 4067e81..cbec4d6 100644
--- a/scribblings/cs019.scrbl
+++ b/scribblings/cs019.scrbl
@@ -76,7 +76,7 @@ Run the following to create the @filepath{whalesong} launcher program in
 your current directory.
 @codeblock|{
 #lang racket/base
-(require (planet dyoo/whalesong:1:9/make-launcher))
+(require (planet dyoo/whalesong:1:10/make-launcher))
 }|
 This may take a few minutes, as Racket is compiling Whalesong, its
 dependencies, and its documentation.  When it finally finishes,