diff --git a/gameforui.go b/gameforui.go
index c99f5e8cd..2367de43e 100644
--- a/gameforui.go
+++ b/gameforui.go
@@ -96,7 +96,7 @@ func (g *gameForUI) NewOffscreenImage(width, height int) *ui.Image {
 	// An image on an atlas is surrounded by a transparent edge,
 	// and the shader program unexpectedly picks the pixel on the edges.
 	imageType := atlas.ImageTypeUnmanaged
-	if ui.IsScreenClearedEveryFrame() {
+	if ui.Get().IsScreenClearedEveryFrame() {
 		// A violatile image is also always isolated.
 		imageType = atlas.ImageTypeVolatile
 	}
diff --git a/graphics.go b/graphics.go
index 721894f68..bd52d9d1e 100644
--- a/graphics.go
+++ b/graphics.go
@@ -66,5 +66,5 @@ type DebugInfo struct {
 
 // ReadDebugInfo writes debug info (e.g. current graphics library) into a provided struct.
 func ReadDebugInfo(d *DebugInfo) {
-	d.GraphicsLibrary = GraphicsLibrary(ui.GetGraphicsLibrary())
+	d.GraphicsLibrary = GraphicsLibrary(ui.Get().GetGraphicsLibrary())
 }
diff --git a/internal/ui/context.go b/internal/ui/context.go
index b2abe987b..93030dea8 100644
--- a/internal/ui/context.go
+++ b/internal/ui/context.go
@@ -141,7 +141,7 @@ func (c *context) updateFrameImpl(graphicsDriver graphicsdriver.Graphics, update
 		}
 
 		// Catch the error that happened at (*Image).At.
-		if err := theGlobalState.error(); err != nil {
+		if err := ui.error(); err != nil {
 			return err
 		}
 	}
@@ -153,7 +153,7 @@ func (c *context) updateFrameImpl(graphicsDriver graphicsdriver.Graphics, update
 	}
 
 	// Draw the game.
-	if err := c.drawGame(graphicsDriver, forceDraw); err != nil {
+	if err := c.drawGame(graphicsDriver, ui, forceDraw); err != nil {
 		return err
 	}
 
@@ -168,8 +168,8 @@ func (c *context) newOffscreenImage(w, h int) *Image {
 	return img
 }
 
-func (c *context) drawGame(graphicsDriver graphicsdriver.Graphics, forceDraw bool) error {
-	if (c.offscreen.imageType == atlas.ImageTypeVolatile) != theGlobalState.isScreenClearedEveryFrame() {
+func (c *context) drawGame(graphicsDriver graphicsdriver.Graphics, ui *UserInterface, forceDraw bool) error {
+	if (c.offscreen.imageType == atlas.ImageTypeVolatile) != ui.IsScreenClearedEveryFrame() {
 		w, h := c.offscreen.width, c.offscreen.height
 		c.offscreen.MarkDisposed()
 		c.offscreen = c.newOffscreenImage(w, h)
@@ -181,7 +181,7 @@ func (c *context) drawGame(graphicsDriver graphicsdriver.Graphics, forceDraw boo
 	// Even though updateCount == 0, the offscreen is cleared and Draw is called.
 	// Draw should not update the game state and then the screen should not be updated without Update, but
 	// users might want to process something at Draw with the time intervals of FPS.
-	if theGlobalState.isScreenClearedEveryFrame() {
+	if ui.IsScreenClearedEveryFrame() {
 		c.offscreen.clear()
 	}
 
diff --git a/internal/ui/globalstate.go b/internal/ui/globalstate.go
deleted file mode 100644
index 86bc396b8..000000000
--- a/internal/ui/globalstate.go
+++ /dev/null
@@ -1,82 +0,0 @@
-// Copyright 2022 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.
-
-package ui
-
-import (
-	"sync"
-	"sync/atomic"
-)
-
-// TODO: Move theGlobalState to UserInterface's member
-var theGlobalState = globalState{
-	isScreenClearedEveryFrame_: 1,
-	graphicsLibrary_:           int32(GraphicsLibraryUnknown),
-}
-
-// globalState represents a global state in this package.
-// This is available even before the game loop starts.
-type globalState struct {
-	err_ error
-	errM sync.Mutex
-
-	isScreenClearedEveryFrame_ int32
-	graphicsLibrary_           int32
-}
-
-func (g *globalState) error() error {
-	g.errM.Lock()
-	defer g.errM.Unlock()
-	return g.err_
-}
-
-func (g *globalState) setError(err error) {
-	g.errM.Lock()
-	defer g.errM.Unlock()
-	if g.err_ == nil {
-		g.err_ = err
-	}
-}
-
-func (g *globalState) isScreenClearedEveryFrame() bool {
-	return atomic.LoadInt32(&g.isScreenClearedEveryFrame_) != 0
-}
-
-func (g *globalState) setScreenClearedEveryFrame(cleared bool) {
-	v := int32(0)
-	if cleared {
-		v = 1
-	}
-	atomic.StoreInt32(&g.isScreenClearedEveryFrame_, v)
-}
-
-func (g *globalState) setGraphicsLibrary(library GraphicsLibrary) {
-	atomic.StoreInt32(&g.graphicsLibrary_, int32(library))
-}
-
-func (g *globalState) graphicsLibrary() GraphicsLibrary {
-	return GraphicsLibrary(atomic.LoadInt32(&g.graphicsLibrary_))
-}
-
-func IsScreenClearedEveryFrame() bool {
-	return theGlobalState.isScreenClearedEveryFrame()
-}
-
-func SetScreenClearedEveryFrame(cleared bool) {
-	theGlobalState.setScreenClearedEveryFrame(cleared)
-}
-
-func GetGraphicsLibrary() GraphicsLibrary {
-	return theGlobalState.graphicsLibrary()
-}
diff --git a/internal/ui/image.go b/internal/ui/image.go
index 4555deecc..96afb3515 100644
--- a/internal/ui/image.go
+++ b/internal/ui/image.go
@@ -149,7 +149,7 @@ func (i *Image) WritePixels(pix []byte, region image.Rectangle) {
 
 func (i *Image) ReadPixels(pixels []byte, region image.Rectangle) {
 	// Check the error existence and avoid unnecessary calls.
-	if theGlobalState.error() != nil {
+	if i.ui.error() != nil {
 		return
 	}
 
@@ -170,7 +170,7 @@ func (i *Image) ReadPixels(pixels []byte, region image.Rectangle) {
 		if panicOnErrorOnReadingPixels {
 			panic(err)
 		}
-		theGlobalState.setError(err)
+		i.ui.setError(err)
 	}
 }
 
diff --git a/internal/ui/input_glfw.go b/internal/ui/input_glfw.go
index 700b9f80b..5d7abecee 100644
--- a/internal/ui/input_glfw.go
+++ b/internal/ui/input_glfw.go
@@ -139,7 +139,7 @@ func (u *UserInterface) KeyName(key Key) string {
 		}
 		n, err := glfw.GetKeyName(gk, 0)
 		if err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 		name = n
diff --git a/internal/ui/ui.go b/internal/ui/ui.go
index 73225dd95..702a83340 100644
--- a/internal/ui/ui.go
+++ b/internal/ui/ui.go
@@ -17,6 +17,8 @@ package ui
 import (
 	"errors"
 	"image"
+	"sync"
+	"sync/atomic"
 
 	"github.com/hajimehoshi/ebiten/v2/internal/atlas"
 	"github.com/hajimehoshi/ebiten/v2/internal/mipmap"
@@ -67,6 +69,12 @@ const (
 )
 
 type UserInterface struct {
+	err  error
+	errM sync.Mutex
+
+	isScreenClearedEveryFrame int32
+	graphicsLibrary           int32
+
 	whiteImage *Image
 
 	userInterfaceImpl
@@ -91,7 +99,10 @@ func Get() *UserInterface {
 
 // newUserInterface must be called from the main thread.
 func newUserInterface() (*UserInterface, error) {
-	u := &UserInterface{}
+	u := &UserInterface{
+		isScreenClearedEveryFrame: 1,
+		graphicsLibrary:           int32(GraphicsLibraryUnknown),
+	}
 
 	u.whiteImage = u.NewImage(3, 3, atlas.ImageTypeRegular)
 	pix := make([]byte, 4*u.whiteImage.width*u.whiteImage.height)
@@ -131,3 +142,37 @@ type RunOptions struct {
 func InitialWindowPosition(mw, mh, ww, wh int) (x, y int) {
 	return (mw - ww) / 2, (mh - wh) / 3
 }
+
+func (u *UserInterface) error() error {
+	u.errM.Lock()
+	defer u.errM.Unlock()
+	return u.err
+}
+
+func (u *UserInterface) setError(err error) {
+	u.errM.Lock()
+	defer u.errM.Unlock()
+	if u.err == nil {
+		u.err = err
+	}
+}
+
+func (u *UserInterface) IsScreenClearedEveryFrame() bool {
+	return atomic.LoadInt32(&u.isScreenClearedEveryFrame) != 0
+}
+
+func (u *UserInterface) SetScreenClearedEveryFrame(cleared bool) {
+	v := int32(0)
+	if cleared {
+		v = 1
+	}
+	atomic.StoreInt32(&u.isScreenClearedEveryFrame, v)
+}
+
+func (u *UserInterface) setGraphicsLibrary(library GraphicsLibrary) {
+	atomic.StoreInt32(&u.graphicsLibrary, int32(library))
+}
+
+func (u *UserInterface) GetGraphicsLibrary() GraphicsLibrary {
+	return GraphicsLibrary(atomic.LoadInt32(&u.graphicsLibrary))
+}
diff --git a/internal/ui/ui_darwin.go b/internal/ui/ui_darwin.go
index 60797728c..8d8bf8ffe 100644
--- a/internal/ui/ui_darwin.go
+++ b/internal/ui/ui_darwin.go
@@ -122,7 +122,7 @@ func (u *UserInterface) initializePlatform() error {
 				Cmd: sel_windowWillEnterFullScreen,
 				Fn: func(id objc.ID, cmd objc.SEL, notification objc.ID) {
 					if err := u.setOrigWindowPosWithCurrentPos(); err != nil {
-						theGlobalState.setError(err)
+						u.setError(err)
 						return
 					}
 					pushResizableState(id, cocoa.NSNotification{ID: notification}.Object())
@@ -142,7 +142,7 @@ func (u *UserInterface) initializePlatform() error {
 					// In this case, the window size limitation is disabled temporarily.
 					// When exiting from fullscreen, reset the window size limitation.
 					if err := u.updateWindowSizeLimits(); err != nil {
-						theGlobalState.setError(err)
+						u.setError(err)
 						return
 					}
 				},
diff --git a/internal/ui/ui_glfw.go b/internal/ui/ui_glfw.go
index 7bd9b0160..49390d021 100644
--- a/internal/ui/ui_glfw.go
+++ b/internal/ui/ui_glfw.go
@@ -153,7 +153,7 @@ func (u *UserInterface) init() error {
 	}
 	if _, err := glfw.SetMonitorCallback(func(monitor *glfw.Monitor, event glfw.PeripheralEvent) {
 		if err := theMonitors.update(); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 		}
 	}); err != nil {
 		return err
@@ -278,7 +278,7 @@ func (u *UserInterface) Monitor() *Monitor {
 		}
 		m, err := u.currentMonitor()
 		if err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 		monitor = m
@@ -611,7 +611,7 @@ func (u *UserInterface) ScreenSizeInFullscreen() (int, int) {
 		}
 		m, err := u.currentMonitor()
 		if err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 		if m == nil {
@@ -658,7 +658,7 @@ func (u *UserInterface) IsFullscreen() bool {
 		}
 		b, err := u.isFullscreen()
 		if err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 		fullscreen = b
@@ -685,14 +685,14 @@ func (u *UserInterface) SetFullscreen(fullscreen bool) {
 		}
 		f, err := u.isFullscreen()
 		if err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 		if f == fullscreen {
 			return
 		}
 		if err := u.setFullscreen(fullscreen); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 	})
@@ -710,7 +710,7 @@ func (u *UserInterface) IsFocused() bool {
 		}
 		a, err := u.window.GetAttrib(glfw.Focused)
 		if err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 		focused = a == glfw.True
@@ -752,7 +752,7 @@ func (u *UserInterface) SetFPSMode(mode FPSModeType) {
 			return
 		}
 		if err := u.setFPSMode(mode); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 	})
@@ -765,7 +765,7 @@ func (u *UserInterface) ScheduleFrame() {
 	// As the main thread can be blocked, do not check the current FPS mode.
 	// PostEmptyEvent is concurrent safe.
 	if err := glfw.PostEmptyEvent(); err != nil {
-		theGlobalState.setError(err)
+		u.setError(err)
 		return
 	}
 }
@@ -785,7 +785,7 @@ func (u *UserInterface) CursorMode() CursorMode {
 		}
 		m, err := u.window.GetInputMode(glfw.CursorMode)
 		if err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 		mode = m
@@ -818,12 +818,12 @@ func (u *UserInterface) SetCursorMode(mode CursorMode) {
 			return
 		}
 		if err := u.window.SetInputMode(glfw.CursorMode, driverCursorModeToGLFWCursorMode(mode)); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 		if mode == CursorModeVisible {
 			if err := u.window.SetCursor(glfwSystemCursors[u.getCursorShape()]); err != nil {
-				theGlobalState.setError(err)
+				u.setError(err)
 				return
 			}
 		}
@@ -851,7 +851,7 @@ func (u *UserInterface) SetCursorShape(shape CursorShape) {
 			return
 		}
 		if err := u.window.SetCursor(glfwSystemCursors[shape]); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 	})
@@ -872,7 +872,7 @@ func (u *UserInterface) DeviceScaleFactor() float64 {
 		}
 		m, err := u.currentMonitor()
 		if err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 		f = m.deviceScaleFactor()
@@ -969,11 +969,11 @@ func (u *UserInterface) registerWindowCloseCallback() error {
 				return
 			}
 			if err := u.window.Focus(); err != nil {
-				theGlobalState.setError(err)
+				u.setError(err)
 				return
 			}
 			if err := u.window.SetShouldClose(false); err != nil {
-				theGlobalState.setError(err)
+				u.setError(err)
 				return
 			}
 		}
@@ -996,7 +996,7 @@ func (u *UserInterface) registerWindowFramebufferSizeCallback() error {
 		u.defaultFramebufferSizeCallback = func(_ *glfw.Window, w, h int) {
 			f, err := u.isFullscreen()
 			if err != nil {
-				theGlobalState.setError(err)
+				u.setError(err)
 				return
 			}
 			if f {
@@ -1004,7 +1004,7 @@ func (u *UserInterface) registerWindowFramebufferSizeCallback() error {
 			}
 			a, err := u.window.GetAttrib(glfw.Iconified)
 			if err != nil {
-				theGlobalState.setError(err)
+				u.setError(err)
 				return
 			}
 			if a == glfw.True {
@@ -1015,14 +1015,14 @@ func (u *UserInterface) registerWindowFramebufferSizeCallback() error {
 			// See also the implementation in uiContext.updateOffscreen.
 			m, err := u.currentMonitor()
 			if err != nil {
-				theGlobalState.setError(err)
+				u.setError(err)
 				return
 			}
 			s := m.deviceScaleFactor()
 			ww := int(float64(w) / s)
 			wh := int(float64(h) / s)
 			if err := u.setWindowSizeInDIP(ww, wh, false); err != nil {
-				theGlobalState.setError(err)
+				u.setError(err)
 				return
 			}
 		}
@@ -1134,7 +1134,7 @@ func (u *UserInterface) initOnMainThread(options *RunOptions) error {
 		return err
 	}
 	u.graphicsDriver = g
-	theGlobalState.setGraphicsLibrary(lib)
+	u.setGraphicsLibrary(lib)
 	u.graphicsDriver.SetTransparent(options.ScreenTransparent)
 
 	if u.graphicsDriver.IsGL() {
@@ -1322,7 +1322,7 @@ func (u *UserInterface) setFPSMode(fpsMode FPSModeType) error {
 
 // update must be called from the main thread.
 func (u *UserInterface) update() (float64, float64, error) {
-	if err := theGlobalState.error(); err != nil {
+	if err := u.error(); err != nil {
 		return 0, 0, err
 	}
 
@@ -1429,7 +1429,7 @@ func (u *UserInterface) loopGame() (ferr error) {
 	u.renderThread.Call(func() {
 		if u.graphicsDriver.IsGL() {
 			if err := u.window.MakeContextCurrent(); err != nil {
-				theGlobalState.setError(err)
+				u.setError(err)
 				return
 			}
 		}
@@ -1483,13 +1483,13 @@ func (u *UserInterface) updateGame() error {
 		// Call updateVsync even though fpsMode is not updated.
 		// When toggling to fullscreen, vsync state might be reset unexpectedly (#1787).
 		if err := u.updateVsyncOnRenderThread(); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 
 		// This works only for OpenGL.
 		if err := u.swapBuffersOnRenderThread(); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return
 		}
 	}); err != nil {
@@ -1557,7 +1557,7 @@ func (u *UserInterface) updateIconIfNeeded() error {
 	}
 
 	// Catch a possible error at 'At' (#2647).
-	if err := theGlobalState.error(); err != nil {
+	if err := u.error(); err != nil {
 		return err
 	}
 
diff --git a/internal/ui/ui_js.go b/internal/ui/ui_js.go
index 353446e47..d26f97dd5 100644
--- a/internal/ui/ui_js.go
+++ b/internal/ui/ui_js.go
@@ -395,7 +395,7 @@ func (u *UserInterface) loop(game Game) <-chan error {
 
 	var cf js.Func
 	f := func() {
-		if err := theGlobalState.error(); err != nil {
+		if err := u.error(); err != nil {
 			errCh <- err
 			return
 		}
@@ -572,7 +572,7 @@ func (u *UserInterface) setWindowEventHandlers(v js.Value) {
 		// See https://pkg.go.dev/syscall/js#FuncOf.
 		go func() {
 			if err := u.updateImpl(true); err != nil {
-				theGlobalState.setError(err)
+				u.setError(err)
 				return
 			}
 		}()
@@ -589,7 +589,7 @@ func (u *UserInterface) setCanvasEventHandlers(v js.Value) {
 		e := args[0]
 		e.Call("preventDefault")
 		if err := u.updateInputFromEvent(e); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return nil
 		}
 		return nil
@@ -598,7 +598,7 @@ func (u *UserInterface) setCanvasEventHandlers(v js.Value) {
 		e := args[0]
 		e.Call("preventDefault")
 		if err := u.updateInputFromEvent(e); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return nil
 		}
 		return nil
@@ -612,7 +612,7 @@ func (u *UserInterface) setCanvasEventHandlers(v js.Value) {
 		e := args[0]
 		e.Call("preventDefault")
 		if err := u.updateInputFromEvent(e); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return nil
 		}
 		return nil
@@ -621,7 +621,7 @@ func (u *UserInterface) setCanvasEventHandlers(v js.Value) {
 		e := args[0]
 		e.Call("preventDefault")
 		if err := u.updateInputFromEvent(e); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return nil
 		}
 		return nil
@@ -630,7 +630,7 @@ func (u *UserInterface) setCanvasEventHandlers(v js.Value) {
 		e := args[0]
 		e.Call("preventDefault")
 		if err := u.updateInputFromEvent(e); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return nil
 		}
 		return nil
@@ -639,7 +639,7 @@ func (u *UserInterface) setCanvasEventHandlers(v js.Value) {
 		e := args[0]
 		e.Call("preventDefault")
 		if err := u.updateInputFromEvent(e); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return nil
 		}
 		return nil
@@ -653,7 +653,7 @@ func (u *UserInterface) setCanvasEventHandlers(v js.Value) {
 		e := args[0]
 		e.Call("preventDefault")
 		if err := u.updateInputFromEvent(e); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return nil
 		}
 		return nil
@@ -662,7 +662,7 @@ func (u *UserInterface) setCanvasEventHandlers(v js.Value) {
 		e := args[0]
 		e.Call("preventDefault")
 		if err := u.updateInputFromEvent(e); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return nil
 		}
 		return nil
@@ -671,7 +671,7 @@ func (u *UserInterface) setCanvasEventHandlers(v js.Value) {
 		e := args[0]
 		e.Call("preventDefault")
 		if err := u.updateInputFromEvent(e); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 			return nil
 		}
 		return nil
@@ -733,7 +733,7 @@ func (u *UserInterface) forceUpdateOnMinimumFPSMode() {
 	// See https://pkg.go.dev/syscall/js#FuncOf.
 	go func() {
 		if err := u.updateImpl(true); err != nil {
-			theGlobalState.setError(err)
+			u.setError(err)
 		}
 	}()
 }
@@ -755,7 +755,7 @@ func (u *UserInterface) Run(game Game, options *RunOptions) error {
 		return err
 	}
 	u.graphicsDriver = g
-	theGlobalState.setGraphicsLibrary(lib)
+	u.setGraphicsLibrary(lib)
 
 	if bodyStyle := document.Get("body").Get("style"); options.ScreenTransparent {
 		bodyStyle.Set("backgroundColor", "transparent")
diff --git a/internal/ui/ui_mobile.go b/internal/ui/ui_mobile.go
index 1a4f7da80..3360c477d 100644
--- a/internal/ui/ui_mobile.go
+++ b/internal/ui/ui_mobile.go
@@ -288,7 +288,7 @@ func (u *UserInterface) run(game Game, mainloop bool, options *RunOptions) (err
 		return err
 	}
 	u.graphicsDriver = g
-	theGlobalState.setGraphicsLibrary(lib)
+	u.setGraphicsLibrary(lib)
 	close(u.graphicsDriverInitCh)
 
 	// If gomobile-build is used, wait for the outside size fixed.
diff --git a/internal/ui/ui_nintendosdk.go b/internal/ui/ui_nintendosdk.go
index 16ef51e3c..6da66f999 100644
--- a/internal/ui/ui_nintendosdk.go
+++ b/internal/ui/ui_nintendosdk.go
@@ -85,7 +85,7 @@ func (u *UserInterface) Run(game Game, options *RunOptions) error {
 		return err
 	}
 	u.graphicsDriver = g
-	theGlobalState.setGraphicsLibrary(lib)
+	u.setGraphicsLibrary(lib)
 
 	n := C.ebitengine_Initialize()
 	if err := u.egl.init(n); err != nil {
diff --git a/internal/ui/window_glfw.go b/internal/ui/window_glfw.go
index 13228d588..e8ae748c0 100644
--- a/internal/ui/window_glfw.go
+++ b/internal/ui/window_glfw.go
@@ -41,7 +41,7 @@ func (w *glfwWindow) IsDecorated() bool {
 		}
 		a, err := w.ui.window.GetAttrib(glfw.Decorated)
 		if err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 		v = a == glfw.True
@@ -63,7 +63,7 @@ func (w *glfwWindow) SetDecorated(decorated bool) {
 			return
 		}
 		if err := w.ui.setWindowDecorated(decorated); err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 	})
@@ -104,7 +104,7 @@ func (w *glfwWindow) SetResizingMode(mode WindowResizingMode) {
 			return
 		}
 		if err := w.ui.setWindowResizingMode(mode); err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 	})
@@ -124,7 +124,7 @@ func (w *glfwWindow) IsFloating() bool {
 		}
 		a, err := w.ui.window.GetAttrib(glfw.Floating)
 		if err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 		v = a == glfw.True
@@ -145,7 +145,7 @@ func (w *glfwWindow) SetFloating(floating bool) {
 			return
 		}
 		if err := w.ui.setWindowFloating(floating); err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 	})
@@ -168,7 +168,7 @@ func (w *glfwWindow) IsMaximized() bool {
 		}
 		m, err := w.ui.isWindowMaximized()
 		if err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 		v = m
@@ -201,7 +201,7 @@ func (w *glfwWindow) Maximize() {
 			return
 		}
 		if err := w.ui.maximizeWindow(); err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 	})
@@ -218,7 +218,7 @@ func (w *glfwWindow) IsMinimized() bool {
 		}
 		a, err := w.ui.window.GetAttrib(glfw.Iconified)
 		if err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 		v = a == glfw.True
@@ -236,7 +236,7 @@ func (w *glfwWindow) Minimize() {
 			return
 		}
 		if err := w.ui.iconifyWindow(); err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 	})
@@ -258,7 +258,7 @@ func (w *glfwWindow) Restore() {
 			return
 		}
 		if err := w.ui.restoreWindow(); err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 	})
@@ -280,7 +280,7 @@ func (w *glfwWindow) SetMonitor(monitor *Monitor) {
 			return
 		}
 		if err := w.ui.setWindowMonitor(monitor); err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 	})
@@ -300,7 +300,7 @@ func (w *glfwWindow) Position() (int, int) {
 		}
 		f, err := w.ui.isFullscreen()
 		if err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 
@@ -310,14 +310,14 @@ func (w *glfwWindow) Position() (int, int) {
 		} else {
 			x, y, err := w.ui.window.GetPos()
 			if err != nil {
-				theGlobalState.setError(err)
+				w.ui.setError(err)
 				return
 			}
 			wx, wy = x, y
 		}
 		m, err := w.ui.currentMonitor()
 		if err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 		wx -= m.boundsInGLFWPixels.Min.X
@@ -343,11 +343,11 @@ func (w *glfwWindow) SetPosition(x, y int) {
 		}
 		m, err := w.ui.currentMonitor()
 		if err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 		if err := w.ui.setWindowPositionInDIP(x, y, m); err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 	})
@@ -388,14 +388,14 @@ func (w *glfwWindow) SetSize(width, height int) {
 		}
 		m, err := w.ui.isWindowMaximized()
 		if err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 		if m && runtime.GOOS != "darwin" {
 			return
 		}
 		if err := w.ui.setWindowSizeInDIP(width, height, true); err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 	})
@@ -421,7 +421,7 @@ func (w *glfwWindow) SetSizeLimits(minw, minh, maxw, maxh int) {
 			return
 		}
 		if err := w.ui.updateWindowSizeLimits(); err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 	})
@@ -451,7 +451,7 @@ func (w *glfwWindow) SetTitle(title string) {
 			return
 		}
 		if err := w.ui.setWindowTitle(title); err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 	})
@@ -478,7 +478,7 @@ func (w *glfwWindow) SetMousePassthrough(enabled bool) {
 			return
 		}
 		if err := w.ui.setWindowMousePassthrough(enabled); err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 	})
@@ -498,7 +498,7 @@ func (w *glfwWindow) IsMousePassthrough() bool {
 		}
 		a, err := w.ui.window.GetAttrib(glfw.MousePassthrough)
 		if err != nil {
-			theGlobalState.setError(err)
+			w.ui.setError(err)
 			return
 		}
 		v = a == glfw.True
diff --git a/run.go b/run.go
index ad160ed97..f3c6f1160 100644
--- a/run.go
+++ b/run.go
@@ -157,14 +157,14 @@ var (
 //
 // SetScreenClearedEveryFrame is concurrent-safe.
 func SetScreenClearedEveryFrame(cleared bool) {
-	ui.SetScreenClearedEveryFrame(cleared)
+	ui.Get().SetScreenClearedEveryFrame(cleared)
 }
 
 // IsScreenClearedEveryFrame returns true if the frame isn't cleared at the beginning.
 //
 // IsScreenClearedEveryFrame is concurrent-safe.
 func IsScreenClearedEveryFrame() bool {
-	return ui.IsScreenClearedEveryFrame()
+	return ui.Get().IsScreenClearedEveryFrame()
 }
 
 // SetScreenFilterEnabled enables/disables the use of the "screen" filter Ebitengine uses.