diff --git a/internal/ui/ui_glfw.go b/internal/ui/ui_glfw.go
index be9b5834a..c7b2a59ce 100644
--- a/internal/ui/ui_glfw.go
+++ b/internal/ui/ui_glfw.go
@@ -46,14 +46,6 @@ func CurrentUI() UserInterface {
 var glContext *opengl.Context
 
 func GLContext() *opengl.Context {
-	if glContext != nil {
-		return glContext
-	}
-	var err error
-	glContext, err = opengl.NewContext(currentUI.runOnMainThread)
-	if err != nil {
-		panic(err)
-	}
 	return glContext
 }
 
@@ -145,6 +137,13 @@ func (u *userInterface) ScreenScale() float64 {
 }
 
 func (u *userInterface) Start(width, height int, scale float64, title string) error {
+	// GLContext must be created before setting the screen size, which requres
+	// swapping buffers.
+	var err error
+	glContext, err = opengl.NewContext(currentUI.runOnMainThread)
+	if err != nil {
+		return err
+	}
 	if err := u.runOnMainThread(func() error {
 		m := glfw.GetPrimaryMonitor()
 		v := m.GetVideoMode()
diff --git a/internal/ui/ui_js.go b/internal/ui/ui_js.go
index 811e60021..7ddcc0119 100644
--- a/internal/ui/ui_js.go
+++ b/internal/ui/ui_js.go
@@ -139,14 +139,6 @@ func touchEventToTouches(e *js.Object) []touch {
 var glContext *opengl.Context
 
 func GLContext() *opengl.Context {
-	if glContext != nil {
-		return glContext
-	}
-	var err error
-	glContext, err = opengl.NewContext()
-	if err != nil {
-		panic(err)
-	}
 	return glContext
 }
 
@@ -301,6 +293,11 @@ func (u *userInterface) Start(width, height int, scale float64, title string) er
 	doc.Set("title", title)
 	u.setScreenSize(width, height, scale)
 	canvas.Call("focus")
+	var err error
+	glContext, err = opengl.NewContext()
+	if err != nil {
+		return err
+	}
 	return nil
 }
 
diff --git a/internal/ui/ui_mobile.go b/internal/ui/ui_mobile.go
index 47b63a5c2..8e39e3c54 100644
--- a/internal/ui/ui_mobile.go
+++ b/internal/ui/ui_mobile.go
@@ -27,14 +27,6 @@ import (
 var glContext *opengl.Context
 
 func GLContext() *opengl.Context {
-	if glContext != nil {
-		return glContext
-	}
-	var err error
-	glContext, err = opengl.NewContext()
-	if err != nil {
-		panic(err)
-	}
 	return glContext
 }
 
@@ -83,6 +75,11 @@ func (u *userInterface) Start(width, height int, scale float64, title string) er
 	u.height = height
 	u.scale = scale
 	// title is ignored?
+	var err error
+	glContext, err = opengl.NewContext()
+	if err != nil {
+		return err
+	}
 	return nil
 }