diff --git a/edb/testbase/connection.py b/edb/testbase/connection.py
index 50f2aed2949..f304a085b3d 100644
--- a/edb/testbase/connection.py
+++ b/edb/testbase/connection.py
@@ -416,7 +416,10 @@ async def _retry_operation(self, func):
             # since that *ought* to be done at the transaction level.
             # Though in reality in the test suite it is usually done at the
             # test runner level.
-            except errors.TransactionConflictError:
+            except (
+                errors.TransactionConflictError,
+                errors.TransactionSerializationError,
+            ):
                 if i >= 5 or self.is_in_transaction():
                     raise
                 await asyncio.sleep(