diff --git a/meta-isar/conf/distro/ubuntu-focal.conf b/meta-isar/conf/distro/ubuntu-focal.conf
index 0e4557e..ceb854d 100644
--- a/meta-isar/conf/distro/ubuntu-focal.conf
+++ b/meta-isar/conf/distro/ubuntu-focal.conf
@@ -5,6 +5,7 @@
 
 require conf/distro/debian-common.conf
 
+DISTRO_APT_SOURCES ?= "conf/distro/${DISTRO}.list"
 DISTRO_APT_SOURCES_arm64 ?= "conf/distro/${DISTRO}-ports.list"
 HOST_DISTRO_APT_SOURCES_append_arm64 = " ${DISTRO_APT_SOURCES}"