diff --git a/dom/ipc/BrowserChild.cpp b/dom/ipc/BrowserChild.cpp
index 986746e65d85..0f5301008820 100644
--- a/dom/ipc/BrowserChild.cpp
+++ b/dom/ipc/BrowserChild.cpp
@@ -3251,11 +3251,15 @@ mozilla::ipc::IPCResult BrowserChild::RecvRequestNotifyAfterRemotePaint() {
 
 mozilla::ipc::IPCResult BrowserChild::RecvUIResolutionChanged(
     const float& aDpi, const int32_t& aRounding, const double& aScale) {
+  nsCOMPtr<Document> document(GetTopLevelDocument());
+  if (!document) {
+    return IPC_OK();
+  }
+
   ScreenIntSize oldScreenSize = GetInnerSize();
   if (aDpi > 0) {
     mPuppetWidget->UpdateBackingScaleCache(aDpi, aRounding, aScale);
   }
-  nsCOMPtr<Document> document(GetTopLevelDocument());
   RefPtr<nsPresContext> presContext = document->GetPresContext();
   if (presContext) {
     presContext->UIResolutionChangedSync();
@@ -3278,8 +3282,12 @@ mozilla::ipc::IPCResult BrowserChild::RecvUIResolutionChanged(
 
 mozilla::ipc::IPCResult BrowserChild::RecvThemeChanged(
     nsTArray<LookAndFeelInt>&& aLookAndFeelIntCache) {
-  LookAndFeel::SetIntCache(aLookAndFeelIntCache);
   nsCOMPtr<Document> document(GetTopLevelDocument());
+  if (!document) {
+    return IPC_OK();
+  }
+
+  LookAndFeel::SetIntCache(aLookAndFeelIntCache);
   RefPtr<nsPresContext> presContext = document->GetPresContext();
   if (presContext) {
     presContext->ThemeChanged();