diff --git a/synapse/storage/databases/main/transactions.py b/synapse/storage/databases/main/transactions.py
index d55def4f50..3d9010265c 100644
--- a/synapse/storage/databases/main/transactions.py
+++ b/synapse/storage/databases/main/transactions.py
@@ -160,7 +160,7 @@ class TransactionStore(SQLBaseStore):
             allow_none=True,
         )
 
-        if result and result["retry_last_ts"] > 0:
+        if result and result["retry_last_ts"] and result["retry_last_ts"] > 0:
             return result
         else:
             return None