diff --git a/CHIP-updater/unified-upgrade.sh b/CHIP-updater/unified-upgrade.sh
index 9f3730c..509a50a 100644
--- a/CHIP-updater/unified-upgrade.sh
+++ b/CHIP-updater/unified-upgrade.sh
@@ -73,13 +73,14 @@ Acquire::Check-Valid-Until "false";
 EOF
             ;;
         "buster")
-            # Using current debian mirrors for buster
+            # Using archive mirrors for buster as well
             cat > /etc/apt/sources.list <<EOF
-deb http://deb.debian.org/debian/ buster main
-deb http://security.debian.org/debian-security buster/updates main
+deb http://archive.debian.org/debian/ buster main
+deb http://archive.debian.org/debian-security buster/updates main
 EOF
             ;;
         "bullseye")
+            # Using current debian mirrors for bullseye
             cat > /etc/apt/sources.list <<EOF
 deb http://deb.debian.org/debian bullseye main contrib non-free
 deb http://security.debian.org/debian-security bullseye-security main contrib non-free