diff --git a/internal/graphics/command.go b/internal/graphics/command.go
index cc633c588..5949a4256 100644
--- a/internal/graphics/command.go
+++ b/internal/graphics/command.go
@@ -197,9 +197,8 @@ func (c *fillCommand) Exec(indexOffsetInBytes int) error {
 	if err != nil {
 		return err
 	}
-	if err := f.setAsViewport(); err != nil {
-		return err
-	}
+	f.setAsViewport()
+
 	cr, cg, cb, ca := c.color.R, c.color.G, c.color.B, c.color.A
 	const max = math.MaxUint8
 	r := float64(cr) / max
@@ -235,9 +234,8 @@ func (c *drawImageCommand) Exec(indexOffsetInBytes int) error {
 	if err != nil {
 		return err
 	}
-	if err := f.setAsViewport(); err != nil {
-		return err
-	}
+	f.setAsViewport()
+
 	opengl.GetContext().BlendFunc(c.mode)
 
 	n := c.quadsNum()
@@ -302,9 +300,8 @@ func (c *replacePixelsCommand) Exec(indexOffsetInBytes int) error {
 	if err != nil {
 		return err
 	}
-	if err := f.setAsViewport(); err != nil {
-		return err
-	}
+	f.setAsViewport()
+
 	// Filling with non black or white color is required here for glTexSubImage2D.
 	// Very mysterious but this actually works (Issue #186).
 	// This is needed even after fixing a shader bug at f537378f2a6a8ef56e1acf1c03034967b77c7b51.
diff --git a/internal/graphics/framebuffer.go b/internal/graphics/framebuffer.go
index 2c3e0ef57..acd47631f 100644
--- a/internal/graphics/framebuffer.go
+++ b/internal/graphics/framebuffer.go
@@ -93,9 +93,9 @@ func (f *framebuffer) viewportSize() (int, int) {
 }
 
 // setAsViewport sets the framebuffer as the current viewport.
-func (f *framebuffer) setAsViewport() error {
+func (f *framebuffer) setAsViewport() {
 	w, h := f.viewportSize()
-	return opengl.GetContext().SetViewport(f.native, w, h)
+	opengl.GetContext().SetViewport(f.native, w, h)
 }
 
 // projectionMatrix returns a projection matrix of the framebuffer.
diff --git a/internal/opengl/context.go b/internal/opengl/context.go
index 95fccba5b..5478f4a2b 100644
--- a/internal/opengl/context.go
+++ b/internal/opengl/context.go
@@ -69,16 +69,13 @@ func (c *Context) bindFramebuffer(f Framebuffer) {
 	c.lastFramebuffer = f
 }
 
-func (c *Context) SetViewport(f Framebuffer, width, height int) error {
+func (c *Context) SetViewport(f Framebuffer, width, height int) {
 	c.bindFramebuffer(f)
 	if c.lastViewportWidth != width || c.lastViewportHeight != height {
-		if err := c.setViewportImpl(width, height); err != nil {
-			return nil
-		}
+		c.setViewportImpl(width, height)
 		c.lastViewportWidth = width
 		c.lastViewportHeight = height
 	}
-	return nil
 }
 
 func (c *Context) ScreenFramebuffer() Framebuffer {
diff --git a/internal/opengl/context_desktop.go b/internal/opengl/context_desktop.go
index 8815d8231..16ea2923f 100644
--- a/internal/opengl/context_desktop.go
+++ b/internal/opengl/context_desktop.go
@@ -274,8 +274,8 @@ func (c *Context) NewFramebuffer(texture Texture) (Framebuffer, error) {
 	return framebuffer, nil
 }
 
-func (c *Context) setViewportImpl(width, height int) error {
-	return c.runOnContextThread(func() error {
+func (c *Context) setViewportImpl(width, height int) {
+	_ = c.runOnContextThread(func() error {
 		gl.Viewport(0, 0, int32(width), int32(height))
 		return nil
 	})
diff --git a/internal/opengl/context_js.go b/internal/opengl/context_js.go
index 764b657a5..d20573db2 100644
--- a/internal/opengl/context_js.go
+++ b/internal/opengl/context_js.go
@@ -254,10 +254,9 @@ func (c *Context) NewFramebuffer(t Texture) (Framebuffer, error) {
 	return Framebuffer{f}, nil
 }
 
-func (c *Context) setViewportImpl(width, height int) error {
+func (c *Context) setViewportImpl(width, height int) {
 	gl := c.gl
 	gl.Viewport(0, 0, width, height)
-	return nil
 }
 
 func (c *Context) FillFramebuffer(r, g, b, a float64) error {
diff --git a/internal/opengl/context_mobile.go b/internal/opengl/context_mobile.go
index de5c9e532..96d2da0a5 100644
--- a/internal/opengl/context_mobile.go
+++ b/internal/opengl/context_mobile.go
@@ -215,10 +215,9 @@ func (c *Context) NewFramebuffer(texture Texture) (Framebuffer, error) {
 	return Framebuffer(f), nil
 }
 
-func (c *Context) setViewportImpl(width, height int) error {
+func (c *Context) setViewportImpl(width, height int) {
 	gl := c.gl
 	gl.Viewport(0, 0, width, height)
-	return nil
 }
 
 func (c *Context) FillFramebuffer(r, g, b, a float64) error {