diff --git a/pylib/anki/collection.py b/pylib/anki/collection.py
index 3408f2e2a..471f2c5a7 100644
--- a/pylib/anki/collection.py
+++ b/pylib/anki/collection.py
@@ -257,6 +257,7 @@ crt=?, mod=?, scm=?, dty=?, usn=?, ls=?, conf=?""",
             if not self.server:
                 self.db.execute("pragma journal_mode = delete")
             self.backend.close_collection()
+            self.db = None
             self.media.close()
             self._closeLog()