diff --git a/core/src/main/java/google/registry/config/files/default-config.yaml b/core/src/main/java/google/registry/config/files/default-config.yaml
index 97c403008..17dce56b5 100644
--- a/core/src/main/java/google/registry/config/files/default-config.yaml
+++ b/core/src/main/java/google/registry/config/files/default-config.yaml
@@ -193,7 +193,7 @@ hibernate:
   # to true, nested transactions will throw an exception. If set to false, a
   # transaction with the isolation override specified will still execute at the
   # default level (specified below).
-  perTransactionIsolation: false
+  perTransactionIsolation: true
 
   # Make 'SERIALIZABLE' the default isolation level to ensure correctness.
   #