diff --git a/CHANGES.rst b/CHANGES.rst
index 1982214..536345e 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -4,7 +4,8 @@ Changelog
 1.2.4 (unreleased)
 ------------------
 
-- Nothing changed yet.
+- default b_size for bookyngtypesvocab to 100
+  [mamico]
 
 
 1.2.3 (2024-03-13)
diff --git a/src/design/plone/ioprenoto/restapi/serializers/configure.zcml b/src/design/plone/ioprenoto/restapi/serializers/configure.zcml
index 650d83c..beec5aa 100644
--- a/src/design/plone/ioprenoto/restapi/serializers/configure.zcml
+++ b/src/design/plone/ioprenoto/restapi/serializers/configure.zcml
@@ -6,5 +6,6 @@
 
   <include package=".ovverrides" />
 
+  <adapter factory=".vocabularies.SerializeVocabularyToJson" />
 
 </configure>
diff --git a/src/design/plone/ioprenoto/restapi/serializers/vocabularies.py b/src/design/plone/ioprenoto/restapi/serializers/vocabularies.py
new file mode 100644
index 0000000..401b33d
--- /dev/null
+++ b/src/design/plone/ioprenoto/restapi/serializers/vocabularies.py
@@ -0,0 +1,17 @@
+# -*- coding: utf-8 -*-
+from design.plone.ioprenoto.vocabularies.tipologies import IPrenotazioneTypesVocabulary
+from plone.restapi.interfaces import ISerializeToJson
+from plone.restapi.serializer.vocabularies import SerializeVocabularyToJson as Base
+from zope.component import adapter
+from zope.interface import implementer
+from zope.interface import Interface
+
+
+@implementer(ISerializeToJson)
+@adapter(IPrenotazioneTypesVocabulary, Interface)
+class SerializeVocabularyToJson(Base):
+    def __call__(self, vocabulary_id):
+        b_size = self.request.form.get("b_size", "")
+        if not b_size:
+            self.request.form["b_size"] = "200"
+        return super().__call__(vocabulary_id)
diff --git a/src/design/plone/ioprenoto/vocabularies/tipologies.py b/src/design/plone/ioprenoto/vocabularies/tipologies.py
index 47fe997..49e985a 100644
--- a/src/design/plone/ioprenoto/vocabularies/tipologies.py
+++ b/src/design/plone/ioprenoto/vocabularies/tipologies.py
@@ -11,6 +11,15 @@
 from zope.schema.vocabulary import SimpleVocabulary
 
 
+class IPrenotazioneTypesVocabulary(IVocabularyFactory):
+    pass
+
+
+@implementer(IPrenotazioneTypesVocabulary)
+class TypesVocabulary(SimpleVocabulary):
+    pass
+
+
 @implementer(IVocabularyFactory)
 class PrenotazioneTypesVocabulary(object):
     def booking_type2term(self, booking_type):
@@ -48,7 +57,7 @@ def __call__(self, context):
                         if term.value not in [t.value for t in terms]:
                             terms.append(term)
         terms.sort(key=lambda x: x.title)
-        return SimpleVocabulary(terms)
+        return TypesVocabulary(terms)
 
 
 PrenotazioneTypesVocabularyFactory = PrenotazioneTypesVocabulary()