diff --git a/internal/ui/mainloop_gomobilebuild.go b/internal/ui/mainloop_gomobilebuild.go
deleted file mode 100644
index afeba8fc8..000000000
--- a/internal/ui/mainloop_gomobilebuild.go
+++ /dev/null
@@ -1,95 +0,0 @@
-// Copyright 2018 The Ebiten 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.
-
-// +build android ios
-// +build gomobilebuild
-
-package ui
-
-import (
-	"golang.org/x/mobile/app"
-	"golang.org/x/mobile/event/lifecycle"
-	"golang.org/x/mobile/event/paint"
-	"golang.org/x/mobile/event/size"
-	"golang.org/x/mobile/event/touch"
-	"golang.org/x/mobile/gl"
-
-	"github.com/hajimehoshi/ebiten/internal/devicescale"
-	"github.com/hajimehoshi/ebiten/internal/input"
-	"github.com/hajimehoshi/ebiten/internal/opengl"
-)
-
-var (
-	glContextCh chan gl.Context
-)
-
-func appMain(a app.App) {
-	var glctx gl.Context
-	touches := map[touch.Sequence]*input.Touch{}
-	for e := range a.Events() {
-		switch e := a.Filter(e).(type) {
-		case lifecycle.Event:
-			switch e.Crosses(lifecycle.StageVisible) {
-			case lifecycle.CrossOn:
-				glctx, _ = e.DrawContext.(gl.Context)
-				// Assume that glctx is always a same instance.
-				// Then, only once initializing should be enough.
-				if glContextCh != nil {
-					glContextCh <- glctx
-					glContextCh = nil
-				}
-				a.Send(paint.Event{})
-			case lifecycle.CrossOff:
-				glctx = nil
-			}
-		case size.Event:
-			setFullscreen(e.WidthPx, e.HeightPx)
-		case paint.Event:
-			if glctx == nil || e.External {
-				continue
-			}
-			chRender <- struct{}{}
-			<-chRenderEnd
-			a.Publish()
-			a.Send(paint.Event{})
-		case touch.Event:
-			switch e.Type {
-			case touch.TypeBegin, touch.TypeMove:
-				s := devicescale.DeviceScale()
-				x, y := float64(e.X)/s, float64(e.Y)/s
-				// TODO: Is it ok to cast from int64 to int here?
-				t := input.NewTouch(int(e.Sequence), int(x), int(y))
-				touches[e.Sequence] = t
-			case touch.TypeEnd:
-				delete(touches, e.Sequence)
-			}
-			ts := []*input.Touch{}
-			for _, t := range touches {
-				ts = append(ts, t)
-			}
-			UpdateTouches(ts)
-		}
-	}
-}
-
-func RunMainThreadLoop(ch <-chan error) error {
-	glContextCh = make(chan gl.Context)
-	app.Main(appMain)
-	return nil
-}
-
-func initOpenGL() {
-	ctx := <-glContextCh
-	opengl.InitWithContext(ctx)
-}
diff --git a/internal/ui/mainloop_notgomobilebuild.go b/internal/ui/mainloop_notgomobilebuild.go
deleted file mode 100644
index e258f013e..000000000
--- a/internal/ui/mainloop_notgomobilebuild.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Copyright 2018 The Ebiten 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.
-
-// +build android ios
-// +build !gomobilebuild
-
-package ui
-
-import (
-	"errors"
-
-	"github.com/hajimehoshi/ebiten/internal/opengl"
-)
-
-func RunMainThreadLoop(ch <-chan error) error {
-	return errors.New("ui: don't call this: use RunWithoutMainLoop instead of Run")
-}
-
-func initOpenGL() {
-	opengl.Init()
-}
diff --git a/internal/ui/ui_glfw.go b/internal/ui/ui_glfw.go
index 1474acf10..c475380ac 100644
--- a/internal/ui/ui_glfw.go
+++ b/internal/ui/ui_glfw.go
@@ -434,7 +434,7 @@ func SetWindowDecorated(decorated bool) {
 	//     return nil
 }
 
-func Run(width, height int, scale float64, title string, g GraphicsContext) error {
+func Run(width, height int, scale float64, title string, g GraphicsContext, mainloop bool) error {
 	<-currentUIInitialized
 
 	u := currentUI
diff --git a/internal/ui/ui_js.go b/internal/ui/ui_js.go
index e97041baf..7c545a29d 100644
--- a/internal/ui/ui_js.go
+++ b/internal/ui/ui_js.go
@@ -302,7 +302,7 @@ func RunMainThreadLoop(ch <-chan error) error {
 	return <-ch
 }
 
-func Run(width, height int, scale float64, title string, g GraphicsContext) error {
+func Run(width, height int, scale float64, title string, g GraphicsContext, mainloop bool) error {
 	u := currentUI
 	doc := js.Global.Get("document")
 	doc.Set("title", title)
diff --git a/internal/ui/ui_mobile.go b/internal/ui/ui_mobile.go
index 01c2e390c..b97718614 100644
--- a/internal/ui/ui_mobile.go
+++ b/internal/ui/ui_mobile.go
@@ -23,11 +23,25 @@ import (
 	"sync"
 	"time"
 
+	"golang.org/x/mobile/app"
+	"golang.org/x/mobile/event/lifecycle"
+	"golang.org/x/mobile/event/paint"
+	"golang.org/x/mobile/event/size"
+	"golang.org/x/mobile/event/touch"
+	"golang.org/x/mobile/gl"
+
 	"github.com/hajimehoshi/ebiten/internal/devicescale"
 	"github.com/hajimehoshi/ebiten/internal/input"
 	"github.com/hajimehoshi/ebiten/internal/opengl"
 )
 
+var (
+	glContextCh = make(chan gl.Context)
+	renderCh    = make(chan struct{})
+	renderChEnd = make(chan struct{})
+	currentUI   = &userInterface{}
+)
+
 func Render(chError <-chan error) error {
 	runtime.LockOSThread()
 	defer runtime.UnlockOSThread()
@@ -37,8 +51,8 @@ func Render(chError <-chan error) error {
 	}
 	// TODO: Check this is called on the rendering thread
 	select {
-	case chRender <- struct{}{}:
-		return opengl.GetContext().DoWork(chError, chRenderEnd)
+	case renderCh <- struct{}{}:
+		return opengl.GetContext().DoWork(chError, renderChEnd)
 	case <-time.After(500 * time.Millisecond):
 		// This function must not be blocked. We need to break for timeout.
 		return nil
@@ -59,13 +73,57 @@ type userInterface struct {
 	m sync.RWMutex
 }
 
-var (
-	chRender    = make(chan struct{})
-	chRenderEnd = make(chan struct{})
-	currentUI   = &userInterface{}
-)
+// appMain is the main routine for gomobile-build mode.
+func appMain(a app.App) {
+	var glctx gl.Context
+	touches := map[touch.Sequence]*input.Touch{}
+	for e := range a.Events() {
+		switch e := a.Filter(e).(type) {
+		case lifecycle.Event:
+			switch e.Crosses(lifecycle.StageVisible) {
+			case lifecycle.CrossOn:
+				glctx, _ = e.DrawContext.(gl.Context)
+				// Assume that glctx is always a same instance.
+				// Then, only once initializing should be enough.
+				if glContextCh != nil {
+					glContextCh <- glctx
+					glContextCh = nil
+				}
+				a.Send(paint.Event{})
+			case lifecycle.CrossOff:
+				glctx = nil
+			}
+		case size.Event:
+			setFullscreen(e.WidthPx, e.HeightPx)
+		case paint.Event:
+			if glctx == nil || e.External {
+				continue
+			}
+			renderCh <- struct{}{}
+			<-renderChEnd
+			a.Publish()
+			a.Send(paint.Event{})
+		case touch.Event:
+			switch e.Type {
+			case touch.TypeBegin, touch.TypeMove:
+				s := devicescale.DeviceScale()
+				x, y := float64(e.X)/s, float64(e.Y)/s
+				// TODO: Is it ok to cast from int64 to int here?
+				t := input.NewTouch(int(e.Sequence), int(x), int(y))
+				touches[e.Sequence] = t
+			case touch.TypeEnd:
+				delete(touches, e.Sequence)
+			}
+			ts := []*input.Touch{}
+			for _, t := range touches {
+				ts = append(ts, t)
+			}
+			UpdateTouches(ts)
+		}
+	}
+}
 
-func Run(width, height int, scale float64, title string, g GraphicsContext) error {
+func Run(width, height int, scale float64, title string, g GraphicsContext, mainloop bool) error {
 	u := currentUI
 
 	u.m.Lock()
@@ -76,7 +134,12 @@ func Run(width, height int, scale float64, title string, g GraphicsContext) erro
 	u.m.Unlock()
 	// title is ignored?
 
-	initOpenGL()
+	if mainloop {
+		ctx := <-glContextCh
+		opengl.InitWithContext(ctx)
+	} else {
+		opengl.Init()
+	}
 
 	for {
 		if err := u.update(g); err != nil {
@@ -85,6 +148,13 @@ func Run(width, height int, scale float64, title string, g GraphicsContext) erro
 	}
 }
 
+// RunMainThreadLoop runs the main routine for gomobile-build.
+func RunMainThreadLoop(ch <-chan error) error {
+	// TODO: ch should be used
+	app.Main(appMain)
+	return nil
+}
+
 func (u *userInterface) updateGraphicsContext(g GraphicsContext) {
 	sizeChanged := false
 	width, height := 0, 0
@@ -126,9 +196,9 @@ func (u *userInterface) scaleImpl() float64 {
 }
 
 func (u *userInterface) update(g GraphicsContext) error {
-	<-chRender
+	<-renderCh
 	defer func() {
-		chRenderEnd <- struct{}{}
+		renderChEnd <- struct{}{}
 	}()
 
 	u.updateGraphicsContext(g)
diff --git a/run.go b/run.go
index 6158dd2b9..338c3b10f 100644
--- a/run.go
+++ b/run.go
@@ -78,8 +78,8 @@ func IsRunningSlowly() bool {
 
 var theGraphicsContext atomic.Value
 
-func run(width, height int, scale float64, title string, g *graphicsContext) error {
-	if err := ui.Run(width, height, scale, title, g); err != nil {
+func run(width, height int, scale float64, title string, g *graphicsContext, mainloop bool) error {
+	if err := ui.Run(width, height, scale, title, g, mainloop); err != nil {
 		if err == ui.RegularTermination {
 			return nil
 		}
@@ -124,7 +124,7 @@ func Run(f func(*Image) error, width, height int, scale float64, title string) e
 
 		g := newGraphicsContext(f)
 		theGraphicsContext.Store(g)
-		if err := run(width, height, scale, title, g); err != nil {
+		if err := run(width, height, scale, title, g, true); err != nil {
 			ch <- err
 			return
 		}
@@ -148,7 +148,7 @@ func RunWithoutMainLoop(f func(*Image) error, width, height int, scale float64,
 
 		g := newGraphicsContext(f)
 		theGraphicsContext.Store(g)
-		if err := run(width, height, scale, title, g); err != nil {
+		if err := run(width, height, scale, title, g, false); err != nil {
 			ch <- err
 			return
 		}