diff --git a/dom/webgpu/CanvasContext.cpp b/dom/webgpu/CanvasContext.cpp
index 724ea46b2a59..ab42f7c6ffb8 100644
--- a/dom/webgpu/CanvasContext.cpp
+++ b/dom/webgpu/CanvasContext.cpp
@@ -32,7 +32,10 @@ CanvasContext::CanvasContext()
     : mExternalImageId(layers::CompositorManagerChild::GetInstance()
                            ->GetNextExternalImageId()) {}
 
-CanvasContext::~CanvasContext() { Cleanup(); }
+CanvasContext::~CanvasContext() {
+  Cleanup();
+  RemovePostRefreshObserver();
+}
 
 void CanvasContext::Cleanup() {
   if (mSwapChain) {