diff --git a/sdk_container/.repo/manifests/version.txt b/sdk_container/.repo/manifests/version.txt
index d11cbd56ad..22bb812fc3 100644
--- a/sdk_container/.repo/manifests/version.txt
+++ b/sdk_container/.repo/manifests/version.txt
@@ -1,4 +1,4 @@
-FLATCAR_VERSION=4081.2.1
+FLATCAR_VERSION=4081.2.1+nightly-20241217-2100
 FLATCAR_VERSION_ID=4081.2.1
-FLATCAR_BUILD_ID=""
+FLATCAR_BUILD_ID="nightly-20241217-2100"
 FLATCAR_SDK_VERSION=4081.0.0