diff --git a/backend/src/helpers/jest.js b/backend/src/helpers/jest.js
index bb0ab9d7c..e3f6a3c84 100644
--- a/backend/src/helpers/jest.js
+++ b/backend/src/helpers/jest.js
@@ -10,6 +10,7 @@ export function gql(strings) {
 
 // sometime we have to wait to check a db state by having a look into the db in a certain moment
 // or we wait a bit to check if we missed to set an await somewhere
+// see: https://www.sitepoint.com/delay-sleep-pause-wait/
 export function sleep(ms) {
   return new Promise((resolve) => setTimeout(resolve, ms))
 }