diff --git a/mongodb-org/vars/main.yml b/mongodb-org/vars/main.yml
new file mode 100644
index 0000000..4c3d8f8
--- /dev/null
+++ b/mongodb-org/vars/main.yml
@@ -0,0 +1,4 @@
+---
+# IMPORTANT: mongodb does not support ecdsa keys, but it starts anyway without any error.
+letsencrypt_acme_key_type: rsa
+