diff --git a/ts/sql/migrations/1020-self-merges.ts b/ts/sql/migrations/1020-self-merges.ts
new file mode 100644
index 0000000000..184b524c06
--- /dev/null
+++ b/ts/sql/migrations/1020-self-merges.ts
@@ -0,0 +1,54 @@
+// Copyright 2024 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import type { Database } from '@signalapp/better-sqlite3';
+
+import type { LoggerType } from '../../types/Logging';
+import { sql } from '../util';
+import { getOurUuid } from './41-uuid-keys';
+
+export const version = 1020;
+
+export function updateToSchemaVersion1020(
+  currentVersion: number,
+  db: Database,
+  logger: LoggerType
+): void {
+  if (currentVersion >= 1020) {
+    return;
+  }
+
+  db.transaction(() => {
+    const ourAci = getOurUuid(db);
+
+    if (ourAci == null) {
+      logger.info('updateToSchemaVersion1020: not linked');
+      return;
+    }
+
+    const [selectQuery, selectParams] = sql`
+      SELECT id FROM conversations
+      WHERE serviceId IS ${ourAci}
+    `;
+    const ourConversationId = db.prepare(selectQuery).pluck().get(selectParams);
+    if (ourConversationId == null) {
+      logger.error('updateToSchemaVersion1020: no conversation');
+      return;
+    }
+
+    const [deleteQuery, deleteParams] = sql`
+      DELETE FROM messages
+      WHERE
+        conversationId IS ${ourConversationId} AND
+        type IS 'conversation-merge'
+    `;
+    const { changes } = db.prepare(deleteQuery).run(deleteParams);
+    if (changes !== 0) {
+      logger.warn(`updateToSchemaVersion1020: removed ${changes} self merges`);
+    }
+  })();
+
+  db.pragma('user_version = 1020');
+
+  logger.info('updateToSchemaVersion1020: success!');
+}
diff --git a/ts/sql/migrations/index.ts b/ts/sql/migrations/index.ts
index 7a96b30478..f0fbe7f704 100644
--- a/ts/sql/migrations/index.ts
+++ b/ts/sql/migrations/index.ts
@@ -76,10 +76,11 @@ import { updateToSchemaVersion970 } from './970-fts5-optimize';
 import { updateToSchemaVersion980 } from './980-reaction-timestamp';
 import { updateToSchemaVersion990 } from './990-phone-number-sharing';
 import { updateToSchemaVersion1000 } from './1000-mark-unread-call-history-messages-as-unseen';
+import { updateToSchemaVersion1010 } from './1010-call-links-table';
 import {
   version as MAX_VERSION,
-  updateToSchemaVersion1010,
-} from './1010-call-links-table';
+  updateToSchemaVersion1020,
+} from './1020-self-merges';
 
 function updateToSchemaVersion1(
   currentVersion: number,
@@ -2023,6 +2024,7 @@ export const SCHEMA_VERSIONS = [
   updateToSchemaVersion990,
   updateToSchemaVersion1000,
   updateToSchemaVersion1010,
+  updateToSchemaVersion1020,
 ];
 
 export class DBVersionFromFutureError extends Error {
diff --git a/ts/test-node/sql/migration_1020_test.ts b/ts/test-node/sql/migration_1020_test.ts
new file mode 100644
index 0000000000..5c97bea4a8
--- /dev/null
+++ b/ts/test-node/sql/migration_1020_test.ts
@@ -0,0 +1,85 @@
+// Copyright 2024 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+import type { Database } from '@signalapp/better-sqlite3';
+import SQL from '@signalapp/better-sqlite3';
+import { v4 as generateGuid } from 'uuid';
+
+import { normalizeAci } from '../../util/normalizeAci';
+import { insertData, getTableData, updateToVersion } from './helpers';
+
+describe('SQL/updateToSchemaVersion1020', () => {
+  let db: Database;
+
+  const OUR_ACI = normalizeAci(
+    generateGuid(),
+    'updateToSchemaVersion1020 test'
+  );
+  const THEIR_ACI = normalizeAci(
+    generateGuid(),
+    'updateToSchemaVersion1020 test'
+  );
+
+  beforeEach(() => {
+    db = new SQL(':memory:');
+    updateToVersion(db, 1010);
+  });
+
+  afterEach(() => {
+    db.close();
+  });
+
+  it('removes self merges and nothing else', () => {
+    insertData(db, 'items', [
+      {
+        id: 'uuid_id',
+        json: {
+          id: 'uuid_id',
+          value: `${OUR_ACI}.2`,
+        },
+      },
+    ]);
+
+    insertData(db, 'conversations', [
+      {
+        id: 'us',
+        serviceId: OUR_ACI,
+      },
+      {
+        id: 'them',
+        serviceId: THEIR_ACI,
+      },
+    ]);
+
+    insertData(db, 'messages', [
+      {
+        id: 'a',
+        conversationId: 'us',
+        type: 'conversation-merge',
+      },
+      {
+        id: 'b',
+        conversationId: 'us',
+        type: 'incoming',
+      },
+      {
+        id: 'c',
+        conversationId: 'them',
+        type: 'conversation-merge',
+      },
+      {
+        id: 'd',
+        conversationId: 'them',
+        type: 'incoming',
+      },
+    ]);
+
+    updateToVersion(db, 1020);
+
+    assert.deepStrictEqual(
+      getTableData(db, 'messages').map(m => m.id),
+      ['b', 'c', 'd']
+    );
+  });
+});