diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index 8d2206c648..87534b996d 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -1069,8 +1069,10 @@ class Application(QApplication):
         self.ignore_palette_changes = True
         self.setPalette(pal)
         # Needed otherwise Qt does not emit the paletteChanged signal when
-        # appearance is changed.
-        self.setAttribute(Qt.AA_SetPalette, False)
+        # appearance is changed. And it has to be after current event
+        # processing finishes as of Qt 5.14 otherwise the palette change is
+        # ignored.
+        QTimer.singleShot(1000, lambda: QApplication.instance().setAttribute(Qt.AA_SetPalette, False))
         self.ignore_palette_changes = False
 
     def on_palette_change(self):