diff --git a/internal/graphicscommand/image.go b/internal/graphicscommand/image.go
index cc969c7a9..e2ab59a35 100644
--- a/internal/graphicscommand/image.go
+++ b/internal/graphicscommand/image.go
@@ -15,6 +15,7 @@
 package graphicscommand
 
 import (
+	"fmt"
 	"image"
 	"io"
 	"sort"
@@ -204,9 +205,8 @@ func (i *Image) dumpName(path string) string {
 //
 // This is for testing usage.
 func (i *Image) dumpTo(w io.Writer, graphicsDriver graphicsdriver.Graphics, blackbg bool, rect image.Rectangle) error {
-	// Screen image cannot be dumped.
 	if i.screen {
-		return nil
+		return fmt.Errorf("graphicscommand: a screen image cannot be dumped")
 	}
 
 	pix := make([]byte, 4*i.width*i.height)
diff --git a/internal/graphicscommand/image_js.go b/internal/graphicscommand/image_js.go
index 15d8a74b5..210e12357 100644
--- a/internal/graphicscommand/image_js.go
+++ b/internal/graphicscommand/image_js.go
@@ -63,6 +63,11 @@ func DumpImages(images []*Image, graphicsDriver graphicsdriver.Graphics, dir str
 	zw := zip.NewWriter(buf)
 
 	for _, img := range images {
+		// Screen image cannot be dumped.
+		if img.screen {
+			continue
+		}
+
 		f, err := zw.Create(img.dumpName("*.png"))
 		if err != nil {
 			return err