Fix bulk_commit #78
diff --git a/requests_cache/backends/storage/dbdict.py b/requests_cache/backends/storage/dbdict.py
index 0d6ce59..c70a56c 100644
--- a/requests_cache/backends/storage/dbdict.py
+++ b/requests_cache/backends/storage/dbdict.py
@@ -108,8 +108,9 @@
         finally:
             self._bulk_commit = False
             self.can_commit = True
-            self._pending_connection.close()
-            self._pending_connection = None
+            if self._pending_connection is not None:
+                self._pending_connection.close()
+                self._pending_connection = None
 
     def __getitem__(self, key):
         with self.connection() as con:
diff --git a/tests/test_dbdict.py b/tests/test_dbdict.py
index 04987ee..f77385a 100644
--- a/tests/test_dbdict.py
+++ b/tests/test_dbdict.py
@@ -18,6 +18,8 @@
 
     def test_bulk_commit(self):
         d = DbDict(self.NAMESPACE, self.TABLES[0])
+        with d.bulk_commit():
+            pass
         d.clear()
         n = 1000
         with d.bulk_commit():