diff --git a/cmd/nixgen/main.go b/cmd/nixgen/main.go
index c76bc456d59f37bb2d34dfc0733644899d85ec50..907f1720ee6f38301053c0abdba89e73063705ab 100644
--- a/cmd/nixgen/main.go
+++ b/cmd/nixgen/main.go
@@ -32,7 +32,7 @@ 			return fmt.Errorf("unknown format %q, should be one of [json yaml toml]", s)
 		}
 		return nil
 	}
-	fs.Func("format", "Output format [json, yaml, toml]: default 'json'", formatFunc)
+	fs.Func("format", "Output format", formatFunc)
 	fs.Func("f", "--format", formatFunc)
 	if err := fs.Parse(os.Args[1:]); err != nil {
 		return err