diff --git a/examples/resources/generate.go b/examples/resources/generate.go
index 181d85afb..c236e300a 100644
--- a/examples/resources/generate.go
+++ b/examples/resources/generate.go
@@ -48,11 +48,3 @@
 //go:generate gofmt -s -w .
 
 package resources
-
-import (
-	// Dummy imports for go.mod for some Go files with 'ignore' tags. For example, `go mod tidy` does not
-	// recognize Go files with 'ignore' build tag.
-	//
-	// Note that this affects only importing this package, but not 'file2byteslice' commands in //go:generate.
-	_ "github.com/hajimehoshi/file2byteslice"
-)
diff --git a/tools.go b/tools.go
new file mode 100644
index 000000000..58f0e77d2
--- /dev/null
+++ b/tools.go
@@ -0,0 +1,24 @@
+// Copyright 2021 The Ebitengine Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build tools
+// +build tools
+
+// This file is to force adding dependencies to go.mod.
+
+package ebiten
+
+import (
+	_ "github.com/hajimehoshi/file2byteslice"
+)