diff --git a/components/compositing/constellation.rs b/components/compositing/constellation.rs
index 1c0e6417df8..dc757202a38 100644
--- a/components/compositing/constellation.rs
+++ b/components/compositing/constellation.rs
@@ -170,12 +170,6 @@ pub struct Constellation<LTF, STF> {
     /// Bits of state used to interact with the webdriver implementation
     webdriver: WebDriverData,
 
-    /// A list of in-process senders to `CanvasPaintThread`s.
-    canvas_paint_threads: Vec<Sender<CanvasMsg>>,
-
-    /// A list of in-process senders to `WebGLPaintThread`s.
-    webgl_paint_threads: Vec<Sender<CanvasMsg>>,
-
     scheduler_chan: IpcSender<TimerEventRequest>,
 
     /// A list of child content processes.
@@ -349,8 +343,6 @@ impl<LTF: LayoutThreadFactory, STF: ScriptThreadFactory> Constellation<LTF, STF>
                     None
                 },
                 webdriver: WebDriverData::new(),
-                canvas_paint_threads: Vec::new(),
-                webgl_paint_threads: Vec::new(),
                 scheduler_chan: TimerScheduler::start(),
                 child_processes: Vec::new(),
                 document_states: HashMap::new(),
@@ -1208,9 +1200,7 @@ impl<LTF: LayoutThreadFactory, STF: ScriptThreadFactory> Constellation<LTF, STF>
             size: &Size2D<i32>,
             response_sender: IpcSender<IpcSender<CanvasMsg>>) {
         let webrender_api = self.webrender_api_sender.clone();
-        let (out_of_process_sender, in_process_sender) = CanvasPaintThread::start(*size,
-                                                                                  webrender_api);
-        self.canvas_paint_threads.push(in_process_sender);
+        let (out_of_process_sender, _) = CanvasPaintThread::start(*size, webrender_api);
         response_sender.send(out_of_process_sender).unwrap()
     }
 
@@ -1221,8 +1211,7 @@ impl<LTF: LayoutThreadFactory, STF: ScriptThreadFactory> Constellation<LTF, STF>
             response_sender: IpcSender<Result<IpcSender<CanvasMsg>, String>>) {
         let webrender_api = self.webrender_api_sender.clone();
         let response = match WebGLPaintThread::start(*size, attributes, webrender_api) {
-            Ok((out_of_process_sender, in_process_sender)) => {
-                self.webgl_paint_threads.push(in_process_sender);
+            Ok((out_of_process_sender, _)) => {
                 Ok(out_of_process_sender)
             },
             Err(msg) => Err(msg),