diff --git a/api/convert_event.go b/api/convert_event.go
index 527236c..5917fc2 100644
--- a/api/convert_event.go
+++ b/api/convert_event.go
@@ -6,6 +6,14 @@ import (
 )
 
 func convertPullRequestEvent(event *structs.PullRequestPayload) *github.PullRequestEvent {
+	if len(event.PullRequest.RequestedReviewers) == 0 {
+		event.PullRequest.RequestedReviewers = append(event.PullRequest.RequestedReviewers, nil)
+	}
+
+	if len(event.PullRequest.Labels) == 0 {
+		event.PullRequest.Labels = append(event.PullRequest.Labels, nil)
+	}
+
 	return &github.PullRequestEvent{
 		Action:            stringPtr(translatePrAction(event.Action)),
 		PullRequest:       convertPullRequest(event.PullRequest),