diff --git a/fuzz.go b/fuzz.go
index eac0e65..69867ef 100644
--- a/fuzz.go
+++ b/fuzz.go
@@ -1,5 +1,6 @@
+//go:build gofuzz
 // +build gofuzz
-//
+
 // To run the fuzzer, run the following commands:
 //		$ GO111MODULE=off go get -u github.com/dvyukov/go-fuzz/go-fuzz github.com/dvyukov/go-fuzz/go-fuzz-build
 //		$ cd $GOPATH/src/github.com/cristalhq/bencode
diff --git a/util_purego.go b/util_purego.go
index 12f0dff..9514fd5 100644
--- a/util_purego.go
+++ b/util_purego.go
@@ -1,3 +1,4 @@
+//go:build purego
 // +build purego
 
 package bencode
diff --git a/util_unsafe.go b/util_unsafe.go
index 926e70a..c0f3fdd 100644
--- a/util_unsafe.go
+++ b/util_unsafe.go
@@ -1,3 +1,4 @@
+//go:build !purego
 // +build !purego
 
 package bencode