diff --git a/Context.go b/Context.go
index c903c0c2..9fc0e392 100644
--- a/Context.go
+++ b/Context.go
@@ -28,7 +28,7 @@ type state struct {
 }
 
 type context struct {
-	backend imgui.Backend
+	backend imgui.Backend[imgui.GLFWWindowFlags]
 
 	// TODO: should be handled by mainthread tbh
 	// see https://github.com/faiface/mainthread/pull/4
@@ -52,7 +52,7 @@ type context struct {
 	m *sync.Mutex
 }
 
-func CreateContext(b imgui.Backend) *context {
+func CreateContext(b imgui.Backend[imgui.GLFWWindowFlags]) *context {
 	result := context{
 		cssStylesheet:       make(cssStylesheet),
 		backend:             b,
diff --git a/MasterWindow.go b/MasterWindow.go
index 9e230ad3..e9cc47e7 100644
--- a/MasterWindow.go
+++ b/MasterWindow.go
@@ -8,34 +8,55 @@ import (
 	"image/color"
 )
 
-// MasterWindowFlags wraps imgui.GLFWWindowFlags.
-type MasterWindowFlags imgui.GLFWWindowFlags
+// MasterWindowFlags implements BackendWindowFlags
+type MasterWindowFlags int
 
 // master window flags.
 const (
 	// Specifies the window will be fixed size.
-	MasterWindowFlagsNotResizable MasterWindowFlags = MasterWindowFlags(imgui.GLFWWindowFlagsNotResizable)
+	MasterWindowFlagsNotResizable MasterWindowFlags = 1 << iota
 	// Specifies whether the window is maximized.
-	MasterWindowFlagsMaximized MasterWindowFlags = MasterWindowFlags(imgui.GLFWWindowFlagsMaximized)
+	MasterWindowFlagsMaximized
 	// Specifies whether the window will be always-on-top.
-	MasterWindowFlagsFloating MasterWindowFlags = MasterWindowFlags(imgui.GLFWWindowFlagsFloating)
+	MasterWindowFlagsFloating
 	// Specifies whether the window will be frameless.
-	MasterWindowFlagsFrameless MasterWindowFlags = MasterWindowFlags(imgui.GLFWWindowFlagsFrameless)
+	MasterWindowFlagsFrameless
 	// Specifies whether the window will be transparent.
-	MasterWindowFlagsTransparent MasterWindowFlags = MasterWindowFlags(imgui.GLFWWindowFlagsTransparent)
+	MasterWindowFlagsTransparent
 )
 
+// parseAndApply converts MasterWindowFlags to appropiate imgui.GLFWWindowFlags.
+func (m MasterWindowFlags) parseAndApply(b imgui.Backend[imgui.GLFWWindowFlags]) {
+	data := map[MasterWindowFlags]struct {
+		f     imgui.GLFWWindowFlags
+		value int // value isn't always true (sometimes false). Also WindowHint takes int not bool
+	}{
+		MasterWindowFlagsNotResizable: {imgui.GLFWWindowFlagsResizable, 0},
+		MasterWindowFlagsMaximized:    {imgui.GLFWWindowFlagsMaximized, 1},
+		MasterWindowFlagsFloating:     {imgui.GLFWWindowFlagsFloating, 1},
+		MasterWindowFlagsFrameless:    {imgui.GLFWWindowFlagsDecorated, 0},
+		MasterWindowFlagsTransparent:  {imgui.GLFWWindowFlagsTransparent, 1},
+	}
+
+	for flag, d := range data {
+		if m&flag != 0 {
+			b.SetWindowFlags(d.f, d.value)
+		}
+	}
+}
+
+// TODO
 // DontCare could be used as an argument to (*MasterWindow).SetSizeLimits.
 // var DontCare int = imgui.GlfwDontCare
 
 // MasterWindow represents a glfw master window
 // It is a base for a windows (see Window.go).
 type MasterWindow struct {
-	backend imgui.Backend
+	backend imgui.Backend[imgui.GLFWWindowFlags]
 
 	width      int
 	height     int
-	clearColor [4]float32
+	clearColor imgui.Vec4
 	title      string
 	context    *imgui.Context
 	io         *imgui.IO
@@ -69,7 +90,7 @@ func NewMasterWindow(title string, width, height int, flags MasterWindowFlags) *
 	Context = CreateContext(backend)
 
 	mw := &MasterWindow{
-		clearColor: [4]float32{0, 0, 0, 1},
+		clearColor: imgui.Vec4{0, 0, 0, 1},
 		width:      width,
 		height:     height,
 		title:      title,
@@ -81,7 +102,8 @@ func NewMasterWindow(title string, width, height int, flags MasterWindowFlags) *
 	backend.SetBeforeRenderHook(mw.beforeRender)
 	backend.SetAfterRenderHook(mw.afterRender)
 	backend.SetBeforeDestroyContextHook(mw.beforeDestroy)
-	backend.CreateWindow(title, width, height, imgui.GLFWWindowFlags(flags))
+	flags.parseAndApply(backend)
+	backend.CreateWindow(title, width, height)
 
 	mw.SetInputHandler(newInputHandler())
 
@@ -241,12 +263,14 @@ func (w *MasterWindow) SetBgColor(bgColor color.Color) {
 	const mask = 0xffff
 
 	r, g, b, a := bgColor.RGBA()
-	w.clearColor = [4]float32{
+	w.clearColor = imgui.Vec4{
 		float32(r) / mask,
 		float32(g) / mask,
 		float32(b) / mask,
 		float32(a) / mask,
 	}
+
+	w.backend.SetBgColor(w.clearColor)
 }
 
 // GetPos return position of master window.
@@ -283,7 +307,7 @@ func (w *MasterWindow) SetSize(x, y int) {
 // Mac OS X: Selecting Quit from the application menu will trigger the close
 // callback for all windows.
 func (w *MasterWindow) SetCloseCallback(cb func() bool) {
-	w.backend.SetCloseCallback(func(b imgui.Backend) {
+	w.backend.SetCloseCallback(func(b imgui.Backend[imgui.GLFWWindowFlags]) {
 		b.SetShouldClose(cb())
 	})
 }
diff --git a/go.mod b/go.mod
index e8061e8f..88ac855f 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module github.com/AllenDang/giu
 go 1.21
 
 require (
-	github.com/AllenDang/cimgui-go v0.0.0-20230914121740-a353600541d2
+	github.com/AllenDang/cimgui-go v0.0.0-20230916161521-36bee41c6188
 	github.com/AllenDang/go-findfont v0.0.0-20200702051237-9f180485aeb8
 	github.com/faiface/mainthread v0.0.0-20171120011319-8b78f0a41ae3
 	github.com/mazznoer/csscolorparser v0.1.3
diff --git a/go.sum b/go.sum
index 687af392..6d7be6d5 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,5 @@
-github.com/AllenDang/cimgui-go v0.0.0-20230914121740-a353600541d2 h1:w5r1Oc6/eUb2AXZRBFga3rae56PpIr8txoJyYxlxQRg=
-github.com/AllenDang/cimgui-go v0.0.0-20230914121740-a353600541d2/go.mod h1:UH0IZCbsJKA1hAVQQU6AIDfamqTk0/d3VucaN8lp1Gs=
+github.com/AllenDang/cimgui-go v0.0.0-20230916161521-36bee41c6188 h1:x5uIiCg1tgFXnn9yq8TGfCWuf25geOQTaiytkJ+c1jw=
+github.com/AllenDang/cimgui-go v0.0.0-20230916161521-36bee41c6188/go.mod h1:UH0IZCbsJKA1hAVQQU6AIDfamqTk0/d3VucaN8lp1Gs=
 github.com/AllenDang/go-findfont v0.0.0-20200702051237-9f180485aeb8 h1:dKZMqib/yUDoCFigmz2agG8geZ/e3iRq304/KJXqKyw=
 github.com/AllenDang/go-findfont v0.0.0-20200702051237-9f180485aeb8/go.mod h1:b4uuDd0s6KRIPa84cEEchdQ9ICh7K0OryZHbSzMca9k=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=