diff --git a/tljh/config_schema.py b/tljh/config_schema.py
index 4a17f13..3e6d8f6 100644
--- a/tljh/config_schema.py
+++ b/tljh/config_schema.py
@@ -74,6 +74,7 @@ config_schema = {
             "type": "object",
             "additionalProperties": False,
             "properties": {"key": {"type": "string"}, "cert": {"type": "string"}},
+            "required": ["key", "cert"],
         },
         "Limits": {
             "description": "User CPU and memory limits.",