diff --git a/tests/lib/nested.sh b/tests/lib/nested.sh
index a07daf6c..2029f083 100644
--- a/tests/lib/nested.sh
+++ b/tests/lib/nested.sh
@@ -112,7 +112,7 @@ start_nested_core_vm_unit(){
 
     # TODO: enable ms key booting for i.e. nightly edge jobs ?
     OVMF_CODE=""
-    OVMF_VARS=""
+    OVMF_VARS="_4M"
     OVMF_VARS_D="/usr/share/OVMF"
     if [ "${ENABLE_SECURE_BOOT:-false}" = "true" ]; then
         OVMF_CODE=".secboot"
@@ -123,7 +123,7 @@ start_nested_core_vm_unit(){
 
     mkdir -p "${WORK_DIR}/image/"
     cp -f "${OVMF_VARS_D}/OVMF_VARS${OVMF_VARS}.fd" "${WORK_DIR}/image/OVMF_VARS${OVMF_VARS}.fd"
-    PARAM_BIOS="-drive file=/usr/share/OVMF/OVMF_CODE${OVMF_CODE}.fd,if=pflash,format=raw,unit=0,readonly=on -drive file=${WORK_DIR}/image/OVMF_VARS${OVMF_VARS}.fd,if=pflash,format=raw"
+    PARAM_BIOS="-drive file=/usr/share/OVMF/OVMF_CODE_4M${OVMF_CODE}.fd,if=pflash,format=raw,unit=0,readonly=on -drive file=${WORK_DIR}/image/OVMF_VARS${OVMF_VARS}.fd,if=pflash,format=raw"
     PARAM_MACHINE="-machine q35${ATTR_KVM} -global ICH9-LPC.disable_s3=1"
 
     # Unfortunately the test-snapd-swtpm snap does not work correctly in lxd
diff --git a/tests/lib/prepare-utils.sh b/tests/lib/prepare-utils.sh
index 32751656..c6b3fbf6 100644
--- a/tests/lib/prepare-utils.sh
+++ b/tests/lib/prepare-utils.sh
@@ -77,8 +77,8 @@ start_snapd_core_vm() {
     fi
 
     mkdir -p "${work_dir}/image/"
-    cp -f "/usr/share/OVMF/OVMF_VARS.fd" "${work_dir}/image/OVMF_VARS.fd"
-    PARAM_BIOS="-drive file=/usr/share/OVMF/OVMF_CODE.fd,if=pflash,format=raw,unit=0,readonly=on -drive file=${work_dir}/image/OVMF_VARS.fd,if=pflash,format=raw"
+    cp -f "/usr/share/OVMF/OVMF_VARS_4M.fd" "${work_dir}/image/OVMF_VARS_4M.fd"
+    PARAM_BIOS="-drive file=/usr/share/OVMF/OVMF_CODE_4M.fd,if=pflash,format=raw,unit=0,readonly=on -drive file=${work_dir}/image/OVMF_VARS_4M.fd,if=pflash,format=raw"
     PARAM_MACHINE="-machine q35${ATTR_KVM} -global ICH9-LPC.disable_s3=1"
     PARAM_IMAGE="-drive file=${work_dir}/pc.img,cache=none,format=raw,id=disk1,if=none -device virtio-blk-pci,drive=disk1,bootindex=1"