diff --git a/extensions/matrix/src/matrix/direct-management.test.ts b/extensions/matrix/src/matrix/direct-management.test.ts
index 2d3753789d9..88b092f3f8f 100644
--- a/extensions/matrix/src/matrix/direct-management.test.ts
+++ b/extensions/matrix/src/matrix/direct-management.test.ts
@@ -210,6 +210,37 @@ describe("repairMatrixDirectRooms", () => {
     );
   });
 
+  it("persists discovered strict rooms alongside an older strict mapped room", async () => {
+    const setAccountData = vi.fn(async () => undefined);
+    const client = createClient({
+      getAccountData: vi.fn(async () => ({
+        "@alice:example.org": ["!older:example.org"],
+      })),
+      getJoinedRooms: vi.fn(async () => ["!older:example.org", "!fresh:example.org"]),
+      getJoinedRoomMembers: vi.fn(async () => ["@bot:example.org", "@alice:example.org"]),
+      setAccountData,
+    });
+
+    const result = await repairMatrixDirectRooms({
+      client,
+      remoteUserId: "@alice:example.org",
+    });
+
+    expect(result.activeRoomId).toBe("!older:example.org");
+    expect(result.discoveredStrictRoomIds).toEqual(["!fresh:example.org"]);
+    expect(result.changed).toBe(true);
+    expect(result.directContentAfter["@alice:example.org"]).toEqual([
+      "!older:example.org",
+      "!fresh:example.org",
+    ]);
+    expect(setAccountData).toHaveBeenCalledWith(
+      EventType.Direct,
+      expect.objectContaining({
+        "@alice:example.org": ["!older:example.org", "!fresh:example.org"],
+      }),
+    );
+  });
+
   it("rejects unqualified Matrix user ids", async () => {
     const client = createClient();
 
diff --git a/extensions/matrix/src/matrix/direct-management.ts b/extensions/matrix/src/matrix/direct-management.ts
index 7eb926d5c73..d6458d2ad67 100644
--- a/extensions/matrix/src/matrix/direct-management.ts
+++ b/extensions/matrix/src/matrix/direct-management.ts
@@ -100,12 +100,14 @@ function normalizeRoomIdList(values: readonly string[]): string[] {
   return normalized;
 }
 
-function hasPrimaryMatrixDirectRoomMapping(params: {
+function hasMatrixDirectRoomMappings(params: {
   directContent: MatrixDirectAccountData;
   remoteUserId: string;
-  roomId: string;
+  roomIds: readonly string[];
 }): boolean {
-  return normalizeMappedRoomIds(params.directContent, params.remoteUserId)[0] === params.roomId;
+  const current = normalizeMappedRoomIds(params.directContent, params.remoteUserId);
+  const next = normalizeRoomIdList([...params.roomIds, ...current]);
+  return current.length === next.length && current.every((roomId, index) => roomId === next[index]);
 }
 
 function resolveDirectAccountDataWriteQueue(client: MatrixClient): KeyedAsyncQueue {
@@ -118,10 +120,10 @@ function resolveDirectAccountDataWriteQueue(client: MatrixClient): KeyedAsyncQue
   return created;
 }
 
-async function writeMatrixDirectRoomMapping(params: {
+async function writeMatrixDirectRoomMappings(params: {
   client: MatrixClient;
   remoteUserId: string;
-  roomId: string;
+  roomIds: readonly string[];
 }): Promise<MatrixDirectRoomMappingWriteResult> {
   return await resolveDirectAccountDataWriteQueue(params.client).enqueue(
     DIRECT_ACCOUNT_DATA_QUEUE_KEY,
@@ -130,12 +132,12 @@ async function writeMatrixDirectRoomMapping(params: {
       const directContentAfter = buildNextDirectContent({
         directContent: directContentBefore,
         remoteUserId: params.remoteUserId,
-        roomId: params.roomId,
+        roomIds: params.roomIds,
       });
-      const changed = !hasPrimaryMatrixDirectRoomMapping({
+      const changed = !hasMatrixDirectRoomMappings({
         directContent: directContentBefore,
         remoteUserId: params.remoteUserId,
-        roomId: params.roomId,
+        roomIds: params.roomIds,
       });
       if (changed) {
         await params.client.setAccountData(EventType.Direct, directContentAfter);
@@ -178,10 +180,10 @@ async function classifyDirectRoomCandidate(params: {
 function buildNextDirectContent(params: {
   directContent: MatrixDirectAccountData;
   remoteUserId: string;
-  roomId: string;
+  roomIds: readonly string[];
 }): MatrixDirectAccountData {
   const current = normalizeMappedRoomIds(params.directContent, params.remoteUserId);
-  const nextRooms = normalizeRoomIdList([params.roomId, ...current]);
+  const nextRooms = normalizeRoomIdList([...params.roomIds, ...current]);
   return {
     ...params.directContent,
     [params.remoteUserId]: nextRooms,
@@ -195,10 +197,10 @@ export async function persistMatrixDirectRoomMapping(params: {
 }): Promise<boolean> {
   const remoteUserId = normalizeRemoteUserId(params.remoteUserId);
   return (
-    await writeMatrixDirectRoomMapping({
+    await writeMatrixDirectRoomMappings({
       client: params.client,
       remoteUserId,
-      roomId: params.roomId,
+      roomIds: [params.roomId],
     })
   ).changed;
 }
@@ -331,10 +333,10 @@ export async function repairMatrixDirectRooms(params: {
       encrypted: params.encrypted === true,
     }));
   const createdRoomId = inspected.activeRoomId ? null : activeRoomId;
-  const mappingWrite = await writeMatrixDirectRoomMapping({
+  const mappingWrite = await writeMatrixDirectRoomMappings({
     client: params.client,
     remoteUserId,
-    roomId: activeRoomId,
+    roomIds: [activeRoomId, ...inspected.discoveredStrictRoomIds],
   });
   return {
     ...inspected,