diff --git a/internal/ui/input.go b/internal/ui/input.go
index cbb263ffc..d96905de7 100644
--- a/internal/ui/input.go
+++ b/internal/ui/input.go
@@ -18,9 +18,19 @@ import (
 	"sync"
 )
 
-var currentInput = &Input{}
+var currentInput = &input{}
 
-type Input struct {
+type Input interface {
+	IsKeyPressed(key Key) bool
+	IsMouseButtonPressed(button MouseButton) bool
+	CursorPosition() (x, y int)
+	GamepadAxis(id int, axis int) float64
+	GamepadAxisNum(id int) int
+	GamepadButtonNum(id int) int
+	IsGamepadButtonPressed(id int, button GamepadButton) bool
+}
+
+type input struct {
 	keyPressed         [256]bool
 	mouseButtonPressed [256]bool
 	cursorX            int
@@ -36,29 +46,29 @@ type gamePad struct {
 	buttonPressed [256]bool
 }
 
-func CurrentInput() *Input {
+func CurrentInput() Input {
 	return currentInput
 }
 
-func (i *Input) IsKeyPressed(key Key) bool {
+func (i *input) IsKeyPressed(key Key) bool {
 	i.m.RLock()
 	defer i.m.RUnlock()
 	return i.keyPressed[key]
 }
 
-func (i *Input) CursorPosition() (x, y int) {
+func (i *input) CursorPosition() (x, y int) {
 	i.m.RLock()
 	defer i.m.RUnlock()
-	return i.cursorX, currentInput.cursorY
+	return i.cursorX, i.cursorY
 }
 
-func (i *Input) IsMouseButtonPressed(button MouseButton) bool {
+func (i *input) IsMouseButtonPressed(button MouseButton) bool {
 	i.m.RLock()
 	defer i.m.RUnlock()
 	return i.mouseButtonPressed[button]
 }
 
-func (i *Input) GamepadAxisNum(id int) int {
+func (i *input) GamepadAxisNum(id int) int {
 	i.m.RLock()
 	defer i.m.RUnlock()
 	if len(i.gamepads) <= id {
@@ -67,7 +77,7 @@ func (i *Input) GamepadAxisNum(id int) int {
 	return i.gamepads[id].axisNum
 }
 
-func (i *Input) GamepadAxis(id int, axis int) float64 {
+func (i *input) GamepadAxis(id int, axis int) float64 {
 	i.m.RLock()
 	defer i.m.RUnlock()
 	if len(i.gamepads) <= id {
@@ -76,7 +86,7 @@ func (i *Input) GamepadAxis(id int, axis int) float64 {
 	return i.gamepads[id].axes[axis]
 }
 
-func (i *Input) GamepadButtonNum(id int) int {
+func (i *input) GamepadButtonNum(id int) int {
 	i.m.RLock()
 	defer i.m.RUnlock()
 	if len(i.gamepads) <= id {
@@ -85,7 +95,7 @@ func (i *Input) GamepadButtonNum(id int) int {
 	return i.gamepads[id].buttonNum
 }
 
-func (i *Input) IsGamepadButtonPressed(id int, button GamepadButton) bool {
+func (i *input) IsGamepadButtonPressed(id int, button GamepadButton) bool {
 	i.m.RLock()
 	defer i.m.RUnlock()
 	if len(i.gamepads) <= id {
diff --git a/internal/ui/input_glfw.go b/internal/ui/input_glfw.go
index 7ff0c1907..2a7f92f86 100644
--- a/internal/ui/input_glfw.go
+++ b/internal/ui/input_glfw.go
@@ -28,7 +28,7 @@ var glfwMouseButtonToMouseButton = map[glfw.MouseButton]MouseButton{
 	glfw.MouseButtonMiddle: MouseButtonMiddle,
 }
 
-func (i *Input) update(window *glfw.Window, scale int) error {
+func (i *input) update(window *glfw.Window, scale int) error {
 	i.m.Lock()
 	defer i.m.Unlock()
 
diff --git a/internal/ui/input_js.go b/internal/ui/input_js.go
index 7d7a4604d..36f5b1dee 100644
--- a/internal/ui/input_js.go
+++ b/internal/ui/input_js.go
@@ -20,7 +20,7 @@ import (
 	"github.com/gopherjs/gopherjs/js"
 )
 
-func (i *Input) KeyDown(key int) {
+func (i *input) keyDown(key int) {
 	i.m.Lock()
 	defer i.m.Unlock()
 	k, ok := keyCodeToKey[key]
@@ -30,7 +30,7 @@ func (i *Input) KeyDown(key int) {
 	i.keyPressed[k] = true
 }
 
-func (i *Input) KeyUp(key int) {
+func (i *input) keyUp(key int) {
 	i.m.Lock()
 	defer i.m.Unlock()
 	k, ok := keyCodeToKey[key]
@@ -40,7 +40,7 @@ func (i *Input) KeyUp(key int) {
 	i.keyPressed[k] = false
 }
 
-func (i *Input) MouseDown(button int) {
+func (i *input) mouseDown(button int) {
 	i.m.Lock()
 	defer i.m.Unlock()
 	p := &i.mouseButtonPressed
@@ -54,7 +54,7 @@ func (i *Input) MouseDown(button int) {
 	}
 }
 
-func (i *Input) MouseUp(button int) {
+func (i *input) mouseUp(button int) {
 	i.m.Lock()
 	defer i.m.Unlock()
 	p := &i.mouseButtonPressed
@@ -68,13 +68,13 @@ func (i *Input) MouseUp(button int) {
 	}
 }
 
-func (i *Input) SetMouseCursor(x, y int) {
+func (i *input) setMouseCursor(x, y int) {
 	i.m.Lock()
 	defer i.m.Unlock()
 	i.cursorX, i.cursorY = x, y
 }
 
-func (i *Input) UpdateGamepads() {
+func (i *input) updateGamepads() {
 	i.m.Lock()
 	defer i.m.Unlock()
 	nav := js.Global.Get("navigator")
diff --git a/internal/ui/ui_js.go b/internal/ui/ui_js.go
index 74a0740ae..073d4cc8a 100644
--- a/internal/ui/ui_js.go
+++ b/internal/ui/ui_js.go
@@ -81,7 +81,7 @@ func (u *userInterface) ActualScreenScale() int {
 }
 
 func (u *userInterface) Update() (interface{}, error) {
-	currentInput.UpdateGamepads()
+	currentInput.updateGamepads()
 	if u.sizeChanged {
 		u.sizeChanged = false
 		w, h := u.size()
@@ -165,25 +165,25 @@ func initialize() (*opengl.Context, error) {
 	canvas.Call("addEventListener", "keydown", func(e *js.Object) {
 		e.Call("preventDefault")
 		code := e.Get("keyCode").Int()
-		currentInput.KeyDown(code)
+		currentInput.keyDown(code)
 	})
 	canvas.Call("addEventListener", "keyup", func(e *js.Object) {
 		e.Call("preventDefault")
 		code := e.Get("keyCode").Int()
-		currentInput.KeyUp(code)
+		currentInput.keyUp(code)
 	})
 
 	// Mouse
 	canvas.Call("addEventListener", "mousedown", func(e *js.Object) {
 		e.Call("preventDefault")
 		button := e.Get("button").Int()
-		currentInput.MouseDown(button)
+		currentInput.mouseDown(button)
 		setMouseCursorFromEvent(e)
 	})
 	canvas.Call("addEventListener", "mouseup", func(e *js.Object) {
 		e.Call("preventDefault")
 		button := e.Get("button").Int()
-		currentInput.MouseUp(button)
+		currentInput.mouseUp(button)
 		setMouseCursorFromEvent(e)
 	})
 	canvas.Call("addEventListener", "mousemove", func(e *js.Object) {
@@ -198,14 +198,14 @@ func initialize() (*opengl.Context, error) {
 	// TODO: Create indimendent touch functions
 	canvas.Call("addEventListener", "touchstart", func(e *js.Object) {
 		e.Call("preventDefault")
-		currentInput.MouseDown(0)
+		currentInput.mouseDown(0)
 		touches := e.Get("changedTouches")
 		touch := touches.Index(0)
 		setMouseCursorFromEvent(touch)
 	})
 	canvas.Call("addEventListener", "touchend", func(e *js.Object) {
 		e.Call("preventDefault")
-		currentInput.MouseUp(0)
+		currentInput.mouseUp(0)
 		touches := e.Get("changedTouches")
 		touch := touches.Index(0)
 		setMouseCursorFromEvent(touch)
@@ -238,7 +238,7 @@ func setMouseCursorFromEvent(e *js.Object) {
 	x, y := e.Get("clientX").Int(), e.Get("clientY").Int()
 	x -= rect.Get("left").Int()
 	y -= rect.Get("top").Int()
-	currentInput.SetMouseCursor(x/scale, y/scale)
+	currentInput.setMouseCursor(x/scale, y/scale)
 }
 
 func devicePixelRatio() float64 {