diff --git a/conf/app.src b/conf/app.src
index 8dd27ad..a37017e 100644
--- a/conf/app.src
+++ b/conf/app.src
@@ -1,5 +1,5 @@
 SOURCE_URL=https://releases.rocket.chat/5.1.3/download
-SOURCE_SUM=
+SOURCE_SUM=f08f87cb1fb0d86d2988525f19d115bbed4db61e251901cf932c871e7fd81126
 SOURCE_SUM_PRG=sha256sum
 SOURCE_FORMAT=tar.gz
 SOURCE_IN_SUBDIR=true