diff --git a/nostr.ts b/nostr.ts
index 8a2ae19..618f4d6 160000
--- a/nostr.ts
+++ b/nostr.ts
@@ -1 +1 @@
-Subproject commit 8a2ae19117276ee1c4402dca5550e75abe023778
+Subproject commit 618f4d6baa9e913d6a2674e324d53a219114ea32
diff --git a/resolvers/policy.ts b/resolvers/policy.ts
index 5fb0abc..1a0e705 100644
--- a/resolvers/policy.ts
+++ b/resolvers/policy.ts
@@ -138,6 +138,9 @@ export const add_space_member = (db?: DB): func_AddSpaceMember => async (event:
     if (!db) {
         return new Error("add_space_member is not supported");
     }
+    if (await is_space_member({ db })(event.member)) {
+        return new Error(`${event.member} is already a member of the space.`);
+    }
     db.query(
         `INSERT INTO events_v2(id, pubkey, kind, event) VALUES (?, ?, ?, ?)`,
         [event.id, event.pubkey, event.kind, JSON.stringify(event)],
@@ -145,8 +148,8 @@ export const add_space_member = (db?: DB): func_AddSpaceMember => async (event:
 };
 
 export const is_space_member =
-    (args: { admin: PublicKey; db?: DB }): func_IsSpaceMember => async (pubkey: string) => {
-        if (args.admin.hex === pubkey) return true;
+    (args: { admin?: PublicKey; db?: DB }): func_IsSpaceMember => async (pubkey: string) => {
+        if (args.admin?.hex === pubkey) return true;
 
         if (!args.db) {
             return new Error("is_space_member is not supported");
diff --git a/tests/space-member-test.ts b/tests/space-member-test.ts
index 3f1918f..3ef53a4 100644
--- a/tests/space-member-test.ts
+++ b/tests/space-member-test.ts
@@ -3,7 +3,6 @@ import { InMemoryAccountContext } from "../nostr.ts/nostr.ts";
 import { fail } from "https://deno.land/std@0.202.0/assert/fail.ts";
 import { assertEquals } from "https://deno.land/std@0.220.1/assert/assert_equals.ts";
 import { prepareAddMember } from "../nostr.ts/space-member.ts";
-import { sleep } from "https://raw.githubusercontent.com/BlowaterNostr/csp/master/csp.ts";
 
 const test_ctx = InMemoryAccountContext.Generate();
 const test_kv = async () => {
@@ -38,6 +37,18 @@ Deno.test("Space Member", async (t) => {
         assertEquals(space_members.map((event) => event.id).includes(add_member_event.id), true);
     });
 
+    await t.step("it it already a member", async () => {
+        const redo = await prepareAddMember(test_ctx, new_member.publicKey.hex);
+        if (redo instanceof Error) fail(redo.message);
+        const r = await fetch(`${relay.http_url}`, {
+            method: "POST",
+            body: JSON.stringify(redo),
+        });
+        const message = await r.text();
+        assertEquals(r.status, 400);
+        assertEquals(message, `${new_member.publicKey.hex} is already a member of the space.`);
+    });
+
     await t.step("admin is member", async () => {
         const res = await relay.is_space_member(test_ctx.publicKey.hex);
         if (res instanceof Error) fail(res.message);
diff --git a/tests/test.ts b/tests/test.ts
index 3b234be..c678af3 100644
--- a/tests/test.ts
+++ b/tests/test.ts
@@ -19,6 +19,7 @@ import { prepareNormalNostrEvent } from "../nostr.ts/event.ts";
 import { RelayRejectedEvent, SingleRelayConnection, SubscriptionStream } from "../nostr.ts/relay-single.ts";
 import { PrivateKey, PublicKey } from "../nostr.ts/key.ts";
 import { sleep } from "https://raw.githubusercontent.com/BlowaterNostr/csp/master/csp.ts";
+import { nowRFC3339 } from "../nostr.ts/_helper.ts";
 
 const test_kv = async () => {
     try {
@@ -222,6 +223,7 @@ Deno.test({
                 channel_id: ChannelCreation_event.id,
                 name: "test2",
                 scope: "server",
+                created_at: nowRFC3339(),
             });
             const r2 = await fetch(`${relay.http_url}`, {
                 method: "POST",