diff --git a/spec.bs b/spec.bs
index 3e45c33..1c1c7dd 100644
--- a/spec.bs
+++ b/spec.bs
@@ -58,15 +58,15 @@ A DCAT-AP Feed harvester SHOULD implement the full LDES specification, or re-use
       "EventStream" : "ldes:EventStream",
       "shape": { "@id": "tree:shape", "@type": "@id"},
       "title": "dct:title",
-      "timestampPath": "ldes:timestampPath",
-      "versionOfPath": "ldes:versionOfPath",
+      "timestampPath":  { "@id": "ldes:timestampPath", "@type": "@id"},
+      "versionOfPath": { "@id": "ldes:versionOfPath", "@type": "@id"},
       "view": "tree:view",
       "member": "tree:member",
       "Create": "as:Create",
       "Delete": "as:Delete",
       "Update": "as:Update",
-      "published": "as:published",
-      "object": "as:object",
+      "published": { "@id": "as:published", "@type": "xsd:dateTime"},
+      "object": { "@id": "as:object", "@type": "@id"},
       "dcat":"http://www.w3.org/ns/dcat#"
     },
     "@id": "#Feed",