diff --git a/build/fietsje/transitive.go b/build/fietsje/transitive.go
index 2e2a9f7..6ffd594 100644
--- a/build/fietsje/transitive.go
+++ b/build/fietsje/transitive.go
@@ -18,7 +18,6 @@
 
 import (
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"strings"
@@ -61,7 +60,7 @@
 
 	read := func(p string) []byte {
 		full := fmt.Sprintf("%s/%s", path, p)
-		data, err := ioutil.ReadFile(full)
+		data, err := os.ReadFile(full)
 		if err != nil {
 			panic(fmt.Sprintf("reading file %q: %v", full, err))
 		}