diff --git a/packages/runs/src/runs.mjs b/packages/runs/src/runs.mjs
index 03730c33..d8cb0e58 100644
--- a/packages/runs/src/runs.mjs
+++ b/packages/runs/src/runs.mjs
@@ -32,7 +32,6 @@ export function listRunIds(dataRoot) {
 // One of RUN_DOCUMENTS from a run, or null when it is missing, unreadable,
 // not a JSON object or outside the data root.
 export function readRunDocument(dataRoot, runId, name) {
-  requireRunId(runId);
   if (!RUN_DOCUMENTS.includes(name)) throw new RunsError(`unknown run document: ${JSON.stringify(name)}`);
   return readJsonObject(dataRoot, RUNS_DIRNAME, runId, name);
 }