diff --git a/tools/db_crashtest.py b/tools/db_crashtest.py
index db9978177..1910e4fe8 100644
--- a/tools/db_crashtest.py
+++ b/tools/db_crashtest.py
@@ -315,6 +315,7 @@ ts_params = {
     "use_full_merge_v1": 0,
     "use_txn": 0,
     "read_only": 0,
+    "backup_one_in": 0,
     "secondary_catch_up_one_in": 0,
     "continuous_verification_interval": 0,
     "checkpoint_one_in": 0,