diff --git a/tool/src/build-html-inner.go b/tool/src/build-html-inner.go
index 8d79fbf..1a52144 100644
--- a/tool/src/build-html-inner.go
+++ b/tool/src/build-html-inner.go
@@ -74,7 +74,7 @@ type seg struct {
 
 func main() {
     if len(os.Args) <= 1 {
-        fmt.Fprintln(os.Stderr, "usage: tool/generate *.{go,sh} > output.html")
+        fmt.Fprintln(os.Stderr, "usage: tool/build-html-inner *.{go,sh} > output.html")
         os.Exit(1)
     }