diff --git a/src/runtime.ts b/src/runtime.ts
index ea0d36e..d25fa85 100644
--- a/src/runtime.ts
+++ b/src/runtime.ts
@@ -59,7 +59,14 @@ export async function runTools(opts: RuntimeOptions): Promise<() => void> {
   // both: its tools are the module's and the seat's verbs alike.
   const self = opts.credential?.module;
   const seatNames = new Set((opts.credential?.claims ?? []).map((c) => c.seat));
-  const ownRegistrations = collectTools().filter(({ module }) => module === self || !seatNames.has(module));
+  // A registration under a name that is neither this module nor a seat it claims is not served:
+  // said, and left out, rather than fatal — on 2026-10-01 the credential of a module that had just
+  // learned to implement a seat did not yet name the claim, and the whole runtime restarted for it.
+  const ownRegistrations = collectTools().filter(({ module }) => {
+    if (module === self || !self || seatNames.has(module)) return module === self || !self;
+    console.log(`[mesh-tools] ${self} registers tools under "${module}", which is neither this module nor a seat its credential claims; not served until the mesh issues the claim`);
+    return false;
+  });
   const tools = ownRegistrations.flatMap(({ module, tools: own }) => own.map((t) => ({ module, name: t.name })));
   const stops: Array<() => void> = [];
   const stop = (): void => stops.splice(0).forEach((s) => s());
diff --git a/test/fixtures/store-seat-unclaimed.mjs b/test/fixtures/store-seat-unclaimed.mjs
new file mode 100644
index 0000000..8c6bde4
--- /dev/null
+++ b/test/fixtures/store-seat-unclaimed.mjs
@@ -0,0 +1,12 @@
+// A module that is both software and a role: postgres's own tools under its name, and its
+// implementation of the mesh-store seat's verbs under the seat's (novox/hq ADR 0159, 0160).
+import { registerModuleTools } from "@novox/mesh-sdk/tools";
+
+registerModuleTools("postgres", () => [
+  { name: "postgres_create_database", description: "make one", input: {}, run: async () => ({ made: true }) },
+  { name: "databases", description: "postgres's own listing", input: {}, run: async () => ({ software: "postgres" }) },
+]);
+
+registerModuleTools("mesh-store", () => [
+  { name: "databases", description: "what the store holds", input: {}, run: async () => ({ seat: "mesh-store" }) },
+]);
diff --git a/test/membership.test.ts b/test/membership.test.ts
index 50014e0..2ceb922 100644
--- a/test/membership.test.ts
+++ b/test/membership.test.ts
@@ -195,3 +195,31 @@ test("a mesh that has issued nothing yet gets the derived shape, and says so", a
     await stream.close();
   }
 });
+
+// A module that implements a seat its credential does not (yet) claim is not served for it and does
+// not fall over either: the runtime says so and serves the module's own tools.
+test("a registration under a seat the credential does not claim is said and skipped, not fatal", async (t) => {
+  if (!url) return t.skip("MESH_TEST_NATS unset");
+  resetTools();
+  const stream = await anAssignmentsStream();
+  const credential = { url, node: "anchor", module: "postgres" };
+  const pg = await connectNats(credential);
+  const asker = await connectNats({ url, module: "console", node: "workstation" });
+  const said: string[] = [];
+  const log = console.log;
+  console.log = (...a: unknown[]) => said.push(a.join(" "));
+  let stop = () => {};
+  try {
+    stop = await runTools({ broker: pg, credential, moduleEntrypoints: [fixture("store-seat-unclaimed.mjs")] });
+    console.log = log;
+    assert.ok(said.some((s) => /registers tools under "mesh-store".*not served/.test(s)), said.join("\n"));
+    assert.deepEqual((await callTool(asker, "postgres.databases", {})).result, { software: "postgres" });
+    await assert.rejects(callTool(asker, "seat:mesh-store.databases", {}), /no responders|503/i);
+  } finally {
+    console.log = log;
+    stop();
+    await asker.close();
+    await pg.close();
+    await stream.close();
+  }
+});