diff --git a/core/services_test.go b/core/services_test.go
index d08f3d9d..d33a3d82 100644
--- a/core/services_test.go
+++ b/core/services_test.go
@@ -170,8 +170,7 @@ func TestServiceTotalHits(t *testing.T) {
 
 func TestServiceSum(t *testing.T) {
 	service := SelectService(5)
-	sum, err := service.Sum()
-	assert.Nil(t, err)
+	sum := service.Sum()
 	assert.NotZero(t, sum)
 }