diff --git a/my/spoor/log/activity.json b/my/spoor/log/activity.json
index adb3a1e..2165da1 100644
--- a/my/spoor/log/activity.json
+++ b/my/spoor/log/activity.json
@@ -8,7 +8,7 @@
       "key": "tid",
       "record": {
         "type": "object",
-        "required": ["session", "progress", "createdAt"],
+        "required": ["progress", "createdAt"],
         "nullable": ["performedAt"],
         "properties": {
           "session": { "type": "ref", "ref": "com.atproto.repo.strongRef" },