diff --git a/go.mod b/go.mod
index 7add59019..131e3b8b1 100644
--- a/go.mod
+++ b/go.mod
@@ -2,7 +2,7 @@ module github.com/hajimehoshi/ebiten
 
 require (
 	github.com/go-gl/glfw v0.0.0-20181213070059-819e8ce5125f
-	github.com/gofrs/flock v0.7.0 // indirect
+	github.com/gofrs/flock v0.7.0
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
 	github.com/gopherjs/gopherwasm v1.1.0
 	github.com/hajimehoshi/bitmapfont v1.1.1
@@ -12,7 +12,6 @@ require (
 	github.com/jfreymuth/oggvorbis v1.0.0
 	github.com/jfreymuth/vorbis v1.0.0 // indirect
 	github.com/kr/pretty v0.1.0 // indirect
-	github.com/theckman/go-flock v0.7.0
 	golang.org/x/image v0.0.0-20190118043309-183bebdce1b2
 	golang.org/x/mobile v0.0.0-20190127143845-a42111704963
 	golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4 // indirect
diff --git a/go.sum b/go.sum
index 4dc2d9bb0..0e38b4294 100644
--- a/go.sum
+++ b/go.sum
@@ -29,8 +29,6 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/theckman/go-flock v0.7.0 h1:zsqnXanSTPwZM9l/zx81avzsf5UhGJG+0HxFBaQ5rYo=
-github.com/theckman/go-flock v0.7.0/go.mod h1:kjuth3y9VJ2aNlkNEO99G/8lp9fMIKaGyBmh84IBheM=
 golang.org/x/exp v0.0.0-20180710024300-14dda7b62fcd h1:nLIcFw7GiqKXUS7HiChg6OAYWgASB2H97dZKd1GhDSs=
 golang.org/x/exp v0.0.0-20180710024300-14dda7b62fcd/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/image v0.0.0-20180708004352-c73c2afc3b81/go.mod h1:ux5Hcp/YLpHSI86hEcLt0YII63i6oz57MZXIpbrjZUs=
diff --git a/internal/testflock/flock_notjs.go b/internal/testflock/flock_notjs.go
index b7a4c0617..2e62ec2f6 100644
--- a/internal/testflock/flock_notjs.go
+++ b/internal/testflock/flock_notjs.go
@@ -25,7 +25,7 @@ import (
 	"os"
 	"path/filepath"
 
-	"github.com/theckman/go-flock"
+	"github.com/gofrs/flock"
 )
 
 var theLock = flock.NewFlock(filepath.Join(os.TempDir(), "ebitentest"))