diff --git a/protocol-spec/json-schema/BaseMessage.schema.json b/protocol-spec/json-schema/BaseMessage.schema.json
index 03829ff..f30ff3d 100644
--- a/protocol-spec/json-schema/BaseMessage.schema.json
+++ b/protocol-spec/json-schema/BaseMessage.schema.json
@@ -1,7 +1,7 @@
 {
     "definitions": {},
     "$schema": "http://json-schema.org/draft-07/schema#",
-    "$id": "http://example.com/root.json",
+    "$id": "urn:cadmium:0",
     "type": "object",
     "title": "Base Message Schema",
     "required": [