diff --git a/tests/extmod/btree1.py b/tests/extmod/btree1.py
index 11acd7c98f..a15e537e9e 100644
--- a/tests/extmod/btree1.py
+++ b/tests/extmod/btree1.py
@@ -57,3 +57,5 @@ print(list(db.values()))
 
 for k in db:
     print(k)
+
+db.close()