diff --git a/recipients_app/lib/core/helpers/document_reference_converter.dart b/recipients_app/lib/core/helpers/document_reference_converter.dart
index 2e50af527..607790337 100644
--- a/recipients_app/lib/core/helpers/document_reference_converter.dart
+++ b/recipients_app/lib/core/helpers/document_reference_converter.dart
@@ -2,12 +2,12 @@ import "package:cloud_firestore/cloud_firestore.dart";
 import "package:json_annotation/json_annotation.dart";
 
 class DocumentReferenceConverter
-    implements JsonConverter<DocumentReference, dynamic> {
+    implements JsonConverter<DocumentReference, Object> {
   const DocumentReferenceConverter();
 
   @override
   DocumentReference fromJson(dynamic json) => json as DocumentReference;
 
   @override
-  dynamic toJson(DocumentReference documentReference) => documentReference;
+  Object toJson(DocumentReference documentReference) => documentReference;
 }
diff --git a/recipients_app/lib/core/helpers/timestamp_converter.dart b/recipients_app/lib/core/helpers/timestamp_converter.dart
index 18b0e036a..81bce885d 100644
--- a/recipients_app/lib/core/helpers/timestamp_converter.dart
+++ b/recipients_app/lib/core/helpers/timestamp_converter.dart
@@ -1,16 +1,16 @@
 import "package:cloud_firestore/cloud_firestore.dart";
 import "package:json_annotation/json_annotation.dart";
 
-class TimestampConverter implements JsonConverter<Timestamp?, dynamic> {
+class TimestampConverter implements JsonConverter<Timestamp, Object> {
   const TimestampConverter();
 
   @override
-  Timestamp? fromJson(dynamic json) {
-    return json as Timestamp?;
+  Timestamp fromJson(dynamic json) {
+    return json as Timestamp;
   }
 
   @override
-  dynamic toJson(Timestamp? object) {
+  Object toJson(Timestamp object) {
     return object;
   }
 }
diff --git a/recipients_app/lib/data/models/payment/social_income_payment.g.dart b/recipients_app/lib/data/models/payment/social_income_payment.g.dart
index 09a674f95..7c016f6e0 100644
--- a/recipients_app/lib/data/models/payment/social_income_payment.g.dart
+++ b/recipients_app/lib/data/models/payment/social_income_payment.g.dart
@@ -10,12 +10,14 @@ SocialIncomePayment _$SocialIncomePaymentFromJson(Map<String, dynamic> json) =>
     SocialIncomePayment(
       id: json['id'] as String? ?? '',
       amount: json['amount'] as int?,
-      paymentAt: const TimestampConverter().fromJson(json['payment_at']),
+      paymentAt: _$JsonConverterFromJson<Object, Timestamp>(
+          json['payment_at'], const TimestampConverter().fromJson),
       currency: json['currency'] as String?,
       status: $enumDecodeNullable(_$PaymentStatusEnumMap, json['status']),
       comments: json['comments'] as String?,
       updatedBy: json['last_updated_by'] as String?,
-      updatedAt: const TimestampConverter().fromJson(json['last_updated_at']),
+      updatedAt: _$JsonConverterFromJson<Object, Timestamp>(
+          json['last_updated_at'], const TimestampConverter().fromJson),
     );
 
 Map<String, dynamic> _$SocialIncomePaymentToJson(
@@ -23,14 +25,22 @@ Map<String, dynamic> _$SocialIncomePaymentToJson(
     <String, dynamic>{
       'id': instance.id,
       'amount': instance.amount,
-      'payment_at': const TimestampConverter().toJson(instance.paymentAt),
+      'payment_at': _$JsonConverterToJson<Object, Timestamp>(
+          instance.paymentAt, const TimestampConverter().toJson),
       'currency': instance.currency,
       'status': _$PaymentStatusEnumMap[instance.status],
       'comments': instance.comments,
       'last_updated_by': instance.updatedBy,
-      'last_updated_at': const TimestampConverter().toJson(instance.updatedAt),
+      'last_updated_at': _$JsonConverterToJson<Object, Timestamp>(
+          instance.updatedAt, const TimestampConverter().toJson),
     };
 
+Value? _$JsonConverterFromJson<Json, Value>(
+  Object? json,
+  Value? Function(Json json) fromJson,
+) =>
+    json == null ? null : fromJson(json as Json);
+
 const _$PaymentStatusEnumMap = {
   PaymentStatus.created: 'created',
   PaymentStatus.paid: 'paid',
@@ -39,3 +49,9 @@ const _$PaymentStatusEnumMap = {
   PaymentStatus.failed: 'failed',
   PaymentStatus.other: 'other',
 };
+
+Json? _$JsonConverterToJson<Json, Value>(
+  Value? value,
+  Json? Function(Value value) toJson,
+) =>
+    value == null ? null : toJson(value);
diff --git a/recipients_app/lib/data/models/recipient.g.dart b/recipients_app/lib/data/models/recipient.g.dart
index 2421c2061..4eab738ea 100644
--- a/recipients_app/lib/data/models/recipient.g.dart
+++ b/recipients_app/lib/data/models/recipient.g.dart
@@ -17,7 +17,8 @@ Recipient _$RecipientFromJson(Map<String, dynamic> json) => Recipient(
           : Phone.fromJson(json['mobile_money_phone'] as Map<String, dynamic>),
       firstName: json['first_name'] as String?,
       lastName: json['last_name'] as String?,
-      birthDate: const TimestampConverter().fromJson(json['birth_date']),
+      birthDate: _$JsonConverterFromJson<Object, Timestamp>(
+          json['birth_date'], const TimestampConverter().fromJson),
       email: json['email'] as String?,
       country: json['country'] as String?,
       preferredName: json['preferred_name'] as String?,
@@ -30,9 +31,12 @@ Recipient _$RecipientFromJson(Map<String, dynamic> json) => Recipient(
           json['recipient_since'], const DateTimeConverter().fromJson),
       imLinkInitial: json['im_link_initial'] as String?,
       imLinkRegular: json['im_link_regular'] as String?,
-      nextSurvey: const TimestampConverter().fromJson(json['next_survey']),
+      nextSurvey: _$JsonConverterFromJson<Object, Timestamp>(
+          json['next_survey'], const TimestampConverter().fromJson),
       organizationRef:
-          const DocumentReferenceConverter().fromJson(json['organisation']),
+          _$JsonConverterFromJson<Object, DocumentReference<Object?>>(
+              json['organisation'],
+              const DocumentReferenceConverter().fromJson),
       updatedBy: json['last_updated_by'] as String?,
     );
 
@@ -43,23 +47,23 @@ Map<String, dynamic> _$RecipientToJson(Recipient instance) => <String, dynamic>{
       'paymentProvider': instance.paymentProvider,
       'first_name': instance.firstName,
       'last_name': instance.lastName,
-      'birth_date': const TimestampConverter().toJson(instance.birthDate),
+      'birth_date': _$JsonConverterToJson<Object, Timestamp>(
+          instance.birthDate, const TimestampConverter().toJson),
       'email': instance.email,
       'country': instance.country,
       'preferred_name': instance.preferredName,
       'calling_name': instance.callingName,
       'gender': instance.gender,
       'main_language': instance.selectedLanguage,
-      'organisation':
-          _$JsonConverterToJson<dynamic, DocumentReference<Object?>>(
-              instance.organizationRef,
-              const DocumentReferenceConverter().toJson),
+      'organisation': _$JsonConverterToJson<Object, DocumentReference<Object?>>(
+          instance.organizationRef, const DocumentReferenceConverter().toJson),
       'terms_accepted': instance.termsAccepted,
       'recipient_since': _$JsonConverterToJson<String, DateTime>(
           instance.recipientSince, const DateTimeConverter().toJson),
       'im_link_initial': instance.imLinkInitial,
       'im_link_regular': instance.imLinkRegular,
-      'next_survey': const TimestampConverter().toJson(instance.nextSurvey),
+      'next_survey': _$JsonConverterToJson<Object, Timestamp>(
+          instance.nextSurvey, const TimestampConverter().toJson),
       'last_updated_by': instance.updatedBy,
     };
 
diff --git a/recipients_app/lib/data/models/survey/survey.g.dart b/recipients_app/lib/data/models/survey/survey.g.dart
index 1a55c04a5..c28cf90d9 100644
--- a/recipients_app/lib/data/models/survey/survey.g.dart
+++ b/recipients_app/lib/data/models/survey/survey.g.dart
@@ -9,8 +9,10 @@ part of 'survey.dart';
 Survey _$SurveyFromJson(Map<String, dynamic> json) => Survey(
       id: json['id'] as String? ?? '',
       status: $enumDecodeNullable(_$SurveyServerStatusEnumMap, json['status']),
-      dueDateAt: const TimestampConverter().fromJson(json['due_date_at']),
-      completedAt: const TimestampConverter().fromJson(json['completed_at']),
+      dueDateAt: _$JsonConverterFromJson<Object, Timestamp>(
+          json['due_date_at'], const TimestampConverter().fromJson),
+      completedAt: _$JsonConverterFromJson<Object, Timestamp>(
+          json['completed_at'], const TimestampConverter().fromJson),
       accessEmail: json['access_email'] as String?,
       accessPassword: json['access_pw'] as String?,
     );
@@ -18,8 +20,10 @@ Survey _$SurveyFromJson(Map<String, dynamic> json) => Survey(
 Map<String, dynamic> _$SurveyToJson(Survey instance) => <String, dynamic>{
       'id': instance.id,
       'status': _$SurveyServerStatusEnumMap[instance.status],
-      'due_date_at': const TimestampConverter().toJson(instance.dueDateAt),
-      'completed_at': const TimestampConverter().toJson(instance.completedAt),
+      'due_date_at': _$JsonConverterToJson<Object, Timestamp>(
+          instance.dueDateAt, const TimestampConverter().toJson),
+      'completed_at': _$JsonConverterToJson<Object, Timestamp>(
+          instance.completedAt, const TimestampConverter().toJson),
       'access_email': instance.accessEmail,
       'access_pw': instance.accessPassword,
     };
@@ -32,3 +36,15 @@ const _$SurveyServerStatusEnumMap = {
   SurveyServerStatus.completed: 'completed',
   SurveyServerStatus.missed: 'missed',
 };
+
+Value? _$JsonConverterFromJson<Json, Value>(
+  Object? json,
+  Value? Function(Json json) fromJson,
+) =>
+    json == null ? null : fromJson(json as Json);
+
+Json? _$JsonConverterToJson<Json, Value>(
+  Value? value,
+  Json? Function(Value value) toJson,
+) =>
+    value == null ? null : toJson(value);
diff --git a/recipients_app/pubspec.yaml b/recipients_app/pubspec.yaml
index 84166cb0c..88e1ba982 100644
--- a/recipients_app/pubspec.yaml
+++ b/recipients_app/pubspec.yaml
@@ -2,7 +2,7 @@ name: app
 description: Social Income App
 
 publish_to: "none"
-version: 1.1.8+22
+version: 1.1.8+23
 
 environment:
   sdk: ">=3.1.0 <4.0.0"