diff --git a/ebitenutil/shapes.go b/ebitenutil/shapes.go
index 1cea5ad9b..0027bb96e 100644
--- a/ebitenutil/shapes.go
+++ b/ebitenutil/shapes.go
@@ -28,7 +28,7 @@ var (
 
 func init() {
 	emptyImage, _ = ebiten.NewImage(1, 1)
-	_ = emptyImage.Fill(color.White)
+	emptyImage.Fill(color.White)
 }
 
 // DrawLine draws a line segment on the given destination dst.
diff --git a/image.go b/image.go
index 098a6ac7c..066dbc974 100644
--- a/image.go
+++ b/image.go
@@ -67,23 +67,18 @@ func (i *Image) isSubImage() bool {
 // Clear resets the pixels of the image into 0.
 //
 // When the image is disposed, Clear does nothing.
-//
-// Clear always returns nil as of 1.5.0.
-func (i *Image) Clear() error {
+func (i *Image) Clear() {
 	i.Fill(color.Transparent)
-	return nil
 }
 
 // Fill fills the image with a solid color.
 //
 // When the image is disposed, Fill does nothing.
-//
-// Fill always returns nil as of 1.5.0.
-func (i *Image) Fill(clr color.Color) error {
+func (i *Image) Fill(clr color.Color) {
 	i.copyCheck()
 
 	if i.isDisposed() {
-		return nil
+		return
 	}
 
 	// TODO: Implement this.
@@ -92,7 +87,6 @@ func (i *Image) Fill(clr color.Color) error {
 	}
 
 	i.mipmap.Fill(color.RGBAModel.Convert(clr).(color.RGBA))
-	return nil
 }
 
 func canSkipMipmap(geom GeoM, filter driver.Filter) bool {
diff --git a/image_test.go b/image_test.go
index 1d026476d..443d06d66 100644
--- a/image_test.go
+++ b/image_test.go
@@ -135,14 +135,8 @@ func TestImageComposition(t *testing.T) {
 		return
 	}
 
-	if err := img2.Fill(img2Color); err != nil {
-		t.Fatal(err)
-		return
-	}
-	if err := img3.Fill(img3Color); err != nil {
-		t.Fatal(err)
-		return
-	}
+	img2.Fill(img2Color)
+	img3.Fill(img3Color)
 	img_12_3, err := NewImage(w, h)
 	if err != nil {
 		t.Fatal(err)
@@ -161,14 +155,8 @@ func TestImageComposition(t *testing.T) {
 		return
 	}
 
-	if err := img2.Fill(img2Color); err != nil {
-		t.Fatal(err)
-		return
-	}
-	if err := img3.Fill(img3Color); err != nil {
-		t.Fatal(err)
-		return
-	}
+	img2.Fill(img2Color)
+	img3.Fill(img3Color)
 	img_1_23, err := NewImage(w, h)
 	if err != nil {
 		t.Fatal(err)
@@ -428,10 +416,7 @@ func TestImageCompositeModeLighter(t *testing.T) {
 		t.Fatal(err)
 		return
 	}
-	if err := img1.Fill(color.RGBA{0x01, 0x02, 0x03, 0x04}); err != nil {
-		t.Fatal(err)
-		return
-	}
+	img1.Fill(color.RGBA{0x01, 0x02, 0x03, 0x04})
 	op := &DrawImageOptions{}
 	op.CompositeMode = CompositeModeLighter
 	if err := img1.DrawImage(img0, op); err != nil {
@@ -512,10 +497,7 @@ func TestImageFill(t *testing.T) {
 		return
 	}
 	clr := &mutableRGBA{0x80, 0x80, 0x80, 0x80}
-	if err := img.Fill(clr); err != nil {
-		t.Fatal(err)
-		return
-	}
+	img.Fill(clr)
 	clr.r = 0
 	for j := 0; j < h; j++ {
 		for i := 0; i < w; i++ {