diff --git a/src/calibre/db/cache.py b/src/calibre/db/cache.py
index 0f9c332eda..839854e672 100644
--- a/src/calibre/db/cache.py
+++ b/src/calibre/db/cache.py
@@ -2461,13 +2461,17 @@ class Cache:
             self.shutting_down = True
             self.event_dispatcher.close()
             self._shutdown_fts()
-            from calibre.customize.ui import available_library_closed_plugins
-            for plugin in available_library_closed_plugins():
-                try:
-                    plugin.run(self)
-                except Exception:
-                    import traceback
-                    traceback.print_exc()
+            try:
+                from calibre.customize.ui import available_library_closed_plugins
+            except ImportError:
+                pass  # happens during interpreter shutdown
+            else:
+                for plugin in available_library_closed_plugins():
+                    try:
+                        plugin.run(self)
+                    except Exception:
+                        import traceback
+                        traceback.print_exc()
         self._shutdown_fts(stage=2)
         with self.write_lock:
             self.backend.close()