diff --git a/README.md b/README.md
index 8d8a9b9..bd9989c 100644
--- a/README.md
+++ b/README.md
@@ -75,6 +75,10 @@ CREATE TABLE outbox_events
 The library writes to `id`, `aggregate_id`, `aggregate_type`, `event_type`, `revision`, `aggregate_version`, `payload`,
 and `occurred_at`. It never writes to `created_at`. The database fills it automatically.
 
+`occurred_at` is copied from the record's `occurredAt`, which `tiny-blocks/building-blocks` resolves from the explicit
+argument to `EventRecord::from()`, then the event's own `occurredAt()`, then the current moment. The outbox never reads
+the clock itself.
+
 For aggregates whose identities are not UUID strings, use VARCHAR columns and configure `IdentityColumnType::STRING`
 (see [Customizing the table layout](#customizing-the-table-layout)):
 
diff --git a/composer.json b/composer.json
index 16c4de8..a6118ea 100644
--- a/composer.json
+++ b/composer.json
@@ -32,7 +32,7 @@
         "php": "^8.5",
         "doctrine/dbal": "^4.4",
         "ramsey/uuid": "^4.9",
-        "tiny-blocks/building-blocks": "^5.3",
+        "tiny-blocks/building-blocks": "^6.0",
         "tiny-blocks/collection": "^2.6",
         "tiny-blocks/mapper": "^3.2"
     },