diff --git a/services/tickets/zendesk/service.go b/services/tickets/zendesk/service.go
index 77c1ebc42..becac59dd 100644
--- a/services/tickets/zendesk/service.go
+++ b/services/tickets/zendesk/service.go
@@ -99,12 +99,12 @@ func (s *service) Open(session flows.Session, topic *flows.Topic, body string, a
 		msg.Message = body
 	} else {
 		extra := &struct {
-			Message      string       `json:"message"`
-			Priority     string       `json:"priority"`
-			Subject      string       `json:"subject"`
-			Description  string       `json:"description"`
-			CustomFields []FieldValue `json:"custom_fields"`
-			Tags         []string     `json:"tags"`
+			Message      string      `json:"message"`
+			Priority     string      `json:"priority"`
+			Subject      string      `json:"subject"`
+			Description  string      `json:"description"`
+			CustomFields interface{} `json:"custom_fields"`
+			Tags         []string    `json:"tags"`
 		}{}
 
 		err := jsonx.Unmarshal([]byte(body), extra)
diff --git a/services/tickets/zendesk/service_test.go b/services/tickets/zendesk/service_test.go
index 7ebb9fba3..dd946c926 100644
--- a/services/tickets/zendesk/service_test.go
+++ b/services/tickets/zendesk/service_test.go
@@ -23,7 +23,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-const fieldTicket = `{"message":"Cookies","priority":"high","subject":"Where are my cookies?","description":"I want to know where is my cookie.","tags": ["TAG_01","TAG_02"],"custom_fields":[{"id":"21938362","value":"hd_3000"}]}`
+const fieldTicket = `{"message":"Cookies","priority":"high","subject":"Where are my cookies?","description":"I want to know where is my cookie.","tags": ["TAG_01","TAG_02"],"custom_fields":[{"id":21938362,"value":"hd_3000"}]}`
 
 func TestOpenAndForward(t *testing.T) {
 	ctx, rt, _, _ := testsuite.Get()
diff --git a/services/tickets/zendesk/testdata/TestOpenAndForward_open_ticket.snap b/services/tickets/zendesk/testdata/TestOpenAndForward_open_ticket.snap
index 126754e7d..8b57dd6f7 100644
--- a/services/tickets/zendesk/testdata/TestOpenAndForward_open_ticket.snap
+++ b/services/tickets/zendesk/testdata/TestOpenAndForward_open_ticket.snap
@@ -1,9 +1,9 @@
 POST /api/v2/any_channel/push.json HTTP/1.1
 Host: nyaruka.zendesk.com
 User-Agent: Go-http-client/1.1
-Content-Length: 631
+Content-Length: 697
 Authorization: Bearer ****************
 Content-Type: application/json
 Accept-Encoding: gzip
 
-{"instance_push_id":"1234-abcd","request_id":"sesame:1570461696000000000","external_resources":[{"external_id":"59d74b86-3e2f-4a93-aece-b05d2fdcde0c","message":"Cookies","thread_id":"59d74b86-3e2f-4a93-aece-b05d2fdcde0c","created_at":"2019-10-07T15:21:35Z","author":{"external_id":"5d76d86b-3bb9-4d5a-b822-c9d86f5d8e4f","name":"Ryan Lewis"},"allow_channelback":true,"fields":[{"id":"message","value":"Cookies"},{"id":"priority","value":"high"},{"id":"subject","value":"Where are my cookies?"},{"id":"description","value":"I want to know where is my cookie."},{"id":"custom_fields","value":[{"id":"21938362","value":"hd_3000"}]}]}]}
\ No newline at end of file
+{"instance_push_id":"1234-abcd","request_id":"sesame:1570461696000000000","external_resources":[{"external_id":"59d74b86-3e2f-4a93-aece-b05d2fdcde0c","message":"Cookies","thread_id":"59d74b86-3e2f-4a93-aece-b05d2fdcde0c","created_at":"2019-10-07T15:21:35Z","author":{"external_id":"5d76d86b-3bb9-4d5a-b822-c9d86f5d8e4f","name":"Ryan Lewis"},"allow_channelback":true,"fields":[{"id":"message","value":"Cookies"},{"id":"priority","value":"high"},{"id":"subject","value":"Where are my cookies?"},{"id":"description","value":"I want to know where is my cookie."},{"id":"custom_fields","value":[{"id":21938362,"value":"hd_3000"}]},{"id":"external_id","value":"59d74b86-3e2f-4a93-aece-b05d2fdcde0c"}]}]}
\ No newline at end of file