diff --git a/components/canvas/canvas_data.rs b/components/canvas/canvas_data.rs
index 2c8dbe9981e..492a8da150a 100644
--- a/components/canvas/canvas_data.rs
+++ b/components/canvas/canvas_data.rs
@@ -729,7 +729,7 @@ fn crop_image(
 /// smoothing_enabled: It determines if smoothing is applied to the image result
 fn write_image(
     draw_target: &DrawTarget,
-    mut image_data: Vec<u8>,
+    image_data: Vec<u8>,
     image_size: Size2D<f64>,
     dest_rect: Rect<f64>,
     smoothing_enabled: bool,
@@ -740,8 +740,6 @@ fn write_image(
         return
     }
     let image_rect = Rect::new(Point2D::zero(), image_size);
-    // rgba -> bgra
-    byte_swap(&mut image_data);
 
     // From spec https://html.spec.whatwg.org/multipage/#dom-context-2d-drawimage
     // When scaling up, if the imageSmoothingEnabled attribute is set to true, the user agent should attempt
diff --git a/components/canvas/canvas_paint_thread.rs b/components/canvas/canvas_paint_thread.rs
index ffcabe13174..7f0130e8f3e 100644
--- a/components/canvas/canvas_paint_thread.rs
+++ b/components/canvas/canvas_paint_thread.rs
@@ -132,12 +132,13 @@ impl<'a> CanvasPaintThread <'a> {
                 self.canvas(canvas_id).is_point_in_path(x, y, fill_rule, chan)
             },
             Canvas2dMsg::DrawImage(
-                imagedata,
+                mut imagedata,
                 image_size,
                 dest_rect,
                 source_rect,
                 smoothing_enabled,
             ) => {
+                byte_swap(&mut imagedata);
                 self.canvas(canvas_id).draw_image(
                     imagedata.into(),
                     image_size,
@@ -169,8 +170,6 @@ impl<'a> CanvasPaintThread <'a> {
                 let mut image_data = self.canvas(canvas_id).read_pixels(
                             source_rect.to_i32(),
                             image_size);
-                // TODO: avoid double byte_swap.
-                byte_swap(&mut image_data);
                 self.canvas(other_canvas_id).draw_image(
                     image_data.into(),
                     source_rect.size,