diff --git a/mod-record-specifications-dto/src/main/java/org/folio/rspec/domain/dto/UpdateRequestEvent.java b/mod-record-specifications-dto/src/main/java/org/folio/rspec/domain/dto/UpdateRequestEvent.java
index f38c165..d2b76b9 100644
--- a/mod-record-specifications-dto/src/main/java/org/folio/rspec/domain/dto/UpdateRequestEvent.java
+++ b/mod-record-specifications-dto/src/main/java/org/folio/rspec/domain/dto/UpdateRequestEvent.java
@@ -9,7 +9,8 @@
 @Data
 @JsonTypeInfo(
   use = Id.NAME,
-  property = "definitionType"
+  property = "definitionType",
+  visible = true
 )
 @JsonSubTypes({
   @Type(value = SubfieldUpdateRequestEvent.class, name = "SUBFIELD")
diff --git a/mod-record-specifications-server/src/main/java/org/folio/rspec/service/SpecificationFieldService.java b/mod-record-specifications-server/src/main/java/org/folio/rspec/service/SpecificationFieldService.java
index 40e9643..b17fada 100644
--- a/mod-record-specifications-server/src/main/java/org/folio/rspec/service/SpecificationFieldService.java
+++ b/mod-record-specifications-server/src/main/java/org/folio/rspec/service/SpecificationFieldService.java
@@ -132,6 +132,7 @@ public SubfieldDtoCollection findFieldSubfields(UUID fieldId) {
     );
   }
 
+  @Transactional
   public SubfieldDto saveSubfield(UUID specificationId, String fieldTag, SubfieldDto dto) {
     log.debug("saveSubfield::dto={}", dto);
     return doForFieldOrFail(specificationId, fieldTag,