diff --git a/doc/manual/src/language/index.md b/doc/manual/src/language/index.md
index f9e9b9781..db34fde75 100644
--- a/doc/manual/src/language/index.md
+++ b/doc/manual/src/language/index.md
@@ -93,7 +93,7 @@ This is an incomplete overview of language features, by example.
 
    `"hello ${ { a = "world" }.a }"`
 
-   `"1 2 ${3}"`
+   `"1 2 ${toString 3}"`
 
    `"${pkgs.bash}/bin/sh"`