--- a/widget/windows/nsWindow.cpp
+++ b/widget/windows/nsWindow.cpp
@@ -788,17 +788,18 @@ nsWindow::Create(nsIWidget* aParent,
   DWORD extendedStyle = WindowExStyle();
 
   if (mWindowType == eWindowType_popup) {
     if (!aParent) {
       parent = nullptr;
     }
 
     if (!IsWin8OrLater() &&
-        HasBogusPopupsDropShadowOnMultiMonitor()) {
+        HasBogusPopupsDropShadowOnMultiMonitor() &&
+        ShouldUseOffMainThreadCompositing()) {
       extendedStyle |= WS_EX_COMPOSITED;
     }
 
     if (aInitData->mMouseTransparent) {
       // This flag makes the window transparent to mouse events
       mMouseTransparent = true;
       extendedStyle |= WS_EX_TRANSPARENT;
     }