diff --git a/functions.sh b/functions.sh
index 66f183d..5fc5967 100644
--- a/functions.sh
+++ b/functions.sh
@@ -310,6 +310,7 @@ else:
 oci_push_to_registry () {
     if ! skopeo inspect --format "Image ${1} found on remote container registry." docker://${1}; then
         if podman image exists ${1}; then
+            ensure_variables_are_defined "CONTAINER_REPO_USER CONTAINER_REPO_PASSWORD"
             podman login --username ${CONTAINER_REPO_USER} --password ${CONTAINER_REPO_PASSWORD} ${1%%/*} &&
             # Try x times because of unexplained error 500
             for i in $(seq 1 3); do podman push ${1} && s=0 && break || s=$? && sleep 1; done; (exit $s) &&