diff --git a/buildbot/buildbot_steps.sh b/buildbot/buildbot_steps.sh
index 3e80916..9f97db5 100755
--- a/buildbot/buildbot_steps.sh
+++ b/buildbot/buildbot_steps.sh
@@ -206,6 +206,8 @@ function make_ipxe_efi() {
     embed_file="$(realpath "${embed_file}")"
     signing_cert="$(realpath "${signing_cert}")"
     ca_cert="$(realpath "${ca_cert}")"
+    efi_key="$(realpath "${efi_key}")"
+    efi_cert="$(realpath "${efi_cert}")"
 
     if [ ! -d "$ipxe_src_dir" ]; then
         >&2 echo "IPXE supplied directory does not exist."