diff --git a/services/actions/schedule_tasks.go b/services/actions/schedule_tasks.go
index b2dc3f98407..3a0dff490a4 100644
--- a/services/actions/schedule_tasks.go
+++ b/services/actions/schedule_tasks.go
@@ -132,14 +132,22 @@ func CreateScheduleTask(ctx context.Context, spec *actions_model.ActionScheduleS
 }
 
 func withScheduleInEventPayload(eventPayload, schedule string) string {
-	if schedule == "" || eventPayload == "" {
+	if schedule == "" {
 		return eventPayload
 	}
 
-	event := map[string]any{}
-	if err := json.Unmarshal([]byte(eventPayload), &event); err != nil {
-		log.Error("withScheduleInEventPayload: unmarshal: %v", err)
-		return eventPayload
+	// eventPayload originates from json.Marshal(input.Payload) in handleSchedules,
+	// so a nil payload is stored as the literal "null" and pre-existing rows may be
+	// empty. Both cases start from a fresh map so the schedule field can still be set.
+	var event map[string]any
+	if eventPayload != "" {
+		if err := json.Unmarshal([]byte(eventPayload), &event); err != nil {
+			log.Error("withScheduleInEventPayload: unmarshal: %v", err)
+			return eventPayload
+		}
+	}
+	if event == nil {
+		event = map[string]any{}
 	}
 
 	event["schedule"] = schedule
diff --git a/services/actions/schedule_tasks_test.go b/services/actions/schedule_tasks_test.go
index 770b8426232..f2c7e656e65 100644
--- a/services/actions/schedule_tasks_test.go
+++ b/services/actions/schedule_tasks_test.go
@@ -22,9 +22,20 @@ func TestWithScheduleInEventPayload(t *testing.T) {
 		assert.Equal(t, "refs/heads/main", event["ref"])
 	})
 
-	t.Run("keeps empty payload", func(t *testing.T) {
+	t.Run("adds schedule to null payload", func(t *testing.T) {
+		updated := withScheduleInEventPayload("null", "37 12 5 1 2")
+
+		event := map[string]any{}
+		assert.NoError(t, json.Unmarshal([]byte(updated), &event))
+		assert.Equal(t, "37 12 5 1 2", event["schedule"])
+	})
+
+	t.Run("adds schedule to empty payload", func(t *testing.T) {
 		updated := withScheduleInEventPayload("", "37 12 5 1 2")
-		assert.Empty(t, updated)
+
+		event := map[string]any{}
+		assert.NoError(t, json.Unmarshal([]byte(updated), &event))
+		assert.Equal(t, "37 12 5 1 2", event["schedule"])
 	})
 
 	t.Run("keeps payload when schedule empty", func(t *testing.T) {