diff --git a/packages/backend/src/search/search.controller.spec.ts b/packages/backend/src/search/search.controller.spec.ts
index f4be84d1..0bdf2452 100644
--- a/packages/backend/src/search/search.controller.spec.ts
+++ b/packages/backend/src/search/search.controller.spec.ts
@@ -67,7 +67,7 @@ describe('searchController', () => {
     });
   });
 
-  it('returns only public channel messages when persistence returns mixed channel types', async () => {
+  it('returns messages exactly as provided by persistence', async () => {
     searchMessagesMock.mockResolvedValue({
       messages: [
         { id: 1, message: 'public', name: 'alice', channel: 'C111' },
@@ -82,7 +82,11 @@ describe('searchController', () => {
 
     expect(res.status).toBe(200);
     expect(res.body).toEqual({
-      messages: [{ id: 1, message: 'public', name: 'alice', channel: 'C111' }],
+      messages: [
+        { id: 1, message: 'public', name: 'alice', channel: 'C111' },
+        { id: 2, message: 'private', name: 'bob', channel: 'G222' },
+        { id: 3, message: 'dm', name: 'carol', channel: 'D333' },
+      ],
       mentions: {},
       total: 3,
     });
diff --git a/packages/backend/src/search/search.controller.ts b/packages/backend/src/search/search.controller.ts
index c4a1c4c0..72e4cdd1 100644
--- a/packages/backend/src/search/search.controller.ts
+++ b/packages/backend/src/search/search.controller.ts
@@ -11,8 +11,6 @@ export const searchController: Router = express.Router();
 const searchPersistenceService = new SearchPersistenceService();
 const searchLogger = logger.child({ module: 'SearchController' });
 
-const isPublicChannelId = (value: unknown): boolean => typeof value === 'string' && value.startsWith('C');
-
 searchController.get('/filters', (req: RequestWithAuthSession, res) => {
   const teamId = req.authSession?.teamId;
   if (!teamId) {
@@ -72,11 +70,7 @@ searchController.get('/messages', (req: RequestWithAuthSession, res) => {
       limit: parsedLimit,
       offset: parsedOffset,
     })
-    .then(({ messages, mentions, total }) =>
-      res
-        .status(200)
-        .json({ messages: messages.filter((message) => isPublicChannelId(message.channel)), mentions, total }),
-    )
+    .then(({ messages, mentions, total }) => res.status(200).json({ messages, mentions, total }))
     .catch((e: unknown) => {
       logError(searchLogger, 'Failed to search messages', e, {
         userName,
diff --git a/packages/backend/src/search/search.persistence.service.spec.ts b/packages/backend/src/search/search.persistence.service.spec.ts
index 40cad798..f8353015 100644
--- a/packages/backend/src/search/search.persistence.service.spec.ts
+++ b/packages/backend/src/search/search.persistence.service.spec.ts
@@ -55,7 +55,7 @@ describe('SearchPersistenceService', () => {
     expect(countSql).toContain("message.message != ''");
     expect(countSql).toContain('message.teamId = ?');
     expect(countSql).toContain('slack_user.teamId = ?');
-    expect(countSql).toContain("message.channel LIKE 'C%'");
+    expect(countSql).toContain('INNER JOIN slack_channel ON slack_channel.channelId = message.channel');
     expect(countParams).toEqual(['T1', 'T1']);
 
     expect(dataSql).toContain("message.message != ''");
@@ -90,6 +90,19 @@ describe('SearchPersistenceService', () => {
     expect(dataParams).toEqual(['T1', 'T1', '%general%', '%general%', 100, 0]);
   });
 
+  it('requires channel to exist in slack_channel via INNER JOIN', async () => {
+    query.mockResolvedValueOnce([{ total: 0 }]).mockResolvedValueOnce([]);
+
+    await service.searchMessages({ teamId: 'T1' });
+
+    const [countSql] = (query as Mock).mock.calls[0] as [string, unknown[]];
+    const [dataSql] = (query as Mock).mock.calls[1] as [string, unknown[]];
+
+    expect(countSql).toContain('INNER JOIN slack_channel ON slack_channel.channelId = message.channel');
+    expect(dataSql).toContain('INNER JOIN slack_channel ON slack_channel.channelId = message.channel');
+    expect(dataSql).toContain('slack_channel.name AS channelName');
+  });
+
   it('applies content LIKE filter when content is provided', async () => {
     query.mockResolvedValueOnce([{ total: 0 }]).mockResolvedValueOnce([]);
 
diff --git a/packages/backend/src/search/search.persistence.service.ts b/packages/backend/src/search/search.persistence.service.ts
index c695dc2e..27ebf09c 100644
--- a/packages/backend/src/search/search.persistence.service.ts
+++ b/packages/backend/src/search/search.persistence.service.ts
@@ -46,12 +46,7 @@ export class SearchPersistenceService {
 
     // Each condition is joined with AND in the WHERE clause; filterParams holds the
     // positional `?` values in the same order as the conditions that use them.
-    const conditions: string[] = [
-      "message.message != ''",
-      'message.teamId = ?',
-      'slack_user.teamId = ?',
-      "message.channel LIKE 'C%'",
-    ];
+    const conditions: string[] = ["message.message != ''", 'message.teamId = ?', 'slack_user.teamId = ?'];
     const filterParams: (string | number)[] = [teamId, teamId];
 
     if (userName) {
@@ -75,14 +70,14 @@ export class SearchPersistenceService {
     const joins = `
       FROM message
       INNER JOIN slack_user ON slack_user.id = message.userIdId
-      LEFT JOIN slack_channel ON slack_channel.channelId = message.channel AND slack_channel.teamId = message.teamId
+      INNER JOIN slack_channel ON slack_channel.channelId = message.channel AND slack_channel.teamId = message.teamId
       WHERE ${whereClause}
     `;
 
     const countQuery = `SELECT COUNT(*) AS total ${joins}`;
 
     const dataQuery = `
-      SELECT message.*, slack_user.name, slack_user.slackId, COALESCE(slack_channel.name, message.channel) AS channelName
+      SELECT message.*, slack_user.name, slack_user.slackId, slack_channel.name AS channelName
       ${joins}
       ORDER BY message.createdAt DESC
       LIMIT ?