diff --git a/data/db.js b/data/db.js
index 62b4820..ec8266b 100644
--- a/data/db.js
+++ b/data/db.js
@@ -1,5 +1,7 @@
 "use strict";
 
+import SessionRepo from "/data/session_repo.js";
+
 /** A wrapper around an IndexedDB.
  *
  * This wrapper handles the following tasks:
@@ -19,10 +21,12 @@ export default class WbDb extends EventTarget {
   /** The name of the test `IDBDatabase`. */
   static get DB_NAME_TEST() { return "test-watterblock"; }
   /** The currently correct DB version. */
-  static get DB_VERSION() { return 1; }
+  static get DB_VERSION() { return 2; }
 
   /** The name of the `IDBObjectStore` for `Session`s. */
   static get OS_SESSIONS() { return "sessions"; }
+  /** The name of the `IDBIndex` for the `Session` update time. */
+  static get IDX_SESSIONS_UPDATED() { return "sessions-updated"; }
 
   /** Whether the WbDb constructor may be called. */
   static #mayConstruct = false;
@@ -140,6 +144,11 @@ export default class WbDb extends EventTarget {
 
     if (old < 1 && now >= 1)
       this.#version1(db, trans);
+    if (old < 2 && now >= 2)
+      this.#version2(db, trans);
+
+    // update existing data to be visible in indexes
+    SessionRepo.reinsertAll(trans);
   }
 
   /** Handle the `error` event from opening the DB.
@@ -172,4 +181,14 @@ export default class WbDb extends EventTarget {
       autoIncrement: true,
     });
   }
+
+  /** Do the migration for db version 2.
+   * @param {IDBDatabase} db The db to upgrade.
+   * @param {IDBTransaction} trans The db transaction.
+   */
+  #version2(db, trans) {
+    trans
+      .objectStore(WbDb.OS_SESSIONS)
+      .createIndex(WbDb.IDX_SESSIONS_UPDATED, "updated");
+  }
 }
diff --git a/data/db.test.js b/data/db.test.js
index 672cc89..8fb8d06 100644
--- a/data/db.test.js
+++ b/data/db.test.js
@@ -133,6 +133,45 @@ export default function() {
       assert.true(second.failed, "second instance failed");
     });
 
+    QUnit.test("sessions are reinserted after upgrade", async function(assert) {
+      let first = WbDb.get(true, 1);
+      await waitForChange(first);
+      first
+        .db
+        .transaction([WbDb.OS_SESSIONS], "readwrite")
+        .objectStore(WbDb.OS_SESSIONS)
+        .put({
+          goal: 3,
+          ourTeam: "",
+          theirTeam: "",
+          games: [],
+          currentGame: null,
+        });
+      first.db.close();
+
+      inst = WbDb.get(true, 2);
+      await waitForChange();
+
+      let sessions = (await new Promise(function (resolve) {
+        inst
+          .db
+          .transaction([WbDb.OS_SESSIONS], "readonly")
+          .objectStore(WbDb.OS_SESSIONS)
+          .index(WbDb.IDX_SESSIONS_UPDATED)
+          .getAll()
+          .onsuccess = resolve;
+      })).target.result;
+      assert.strictEqual(sessions.length, 1, "session found by update index");
+
+      // Note that the inserted session data is older than the `updated` field
+      // in the model class. Thus it being present in the index proves that
+      // the session has indeed been parsed and reinserted.
+      //
+      // Also note that the exact parsing and default value adding is already
+      // checked in the model tests, thus it would be a duplicate to test that
+      // here too.
+    });
+
     QUnit.test("schema version 1", async function(assert) {
       inst = WbDb.get(true, 1);
       await waitForChange();
@@ -149,5 +188,32 @@ export default function() {
       assert.true(sessions.autoIncrement, "sessions autoIncrement");
       assert.strictEqual(sessions.indexNames.length, 0, "sessions no indexes");
     });
+
+    QUnit.test("schema version 2", async function(assert) {
+      inst = WbDb.get(true, 2);
+      await waitForChange();
+      assert.true(inst.open, "db is opened");
+      assert.strictEqual(inst.db.version, 2, "db is version 2");
+
+      let osn = inst.db.objectStoreNames;
+      assert.strictEqual(osn.length, 1, "correct number of object stores");
+      assert.true(osn.contains(WbDb.OS_SESSIONS), "contains sessions");
+
+      let trans = inst.db.transaction(osn);
+
+      let sessions = trans.objectStore(WbDb.OS_SESSIONS);
+      assert.strictEqual(sessions.keyPath, "id", "sessions keyPath");
+      assert.true(sessions.autoIncrement, "sessions autoIncrement");
+      assert.strictEqual(sessions.indexNames.length, 1, "sessions one index");
+
+      assert.true(
+        sessions.indexNames.contains(WbDb.IDX_SESSIONS_UPDATED),
+        "sessions contains session updated");
+      let sessionsUpdated = sessions.index(WbDb.IDX_SESSIONS_UPDATED);
+      assert.strictEqual(
+        sessionsUpdated.keyPath, "updated", "sessionsUpdated keyPath");
+      assert.false(sessionsUpdated.unique, "sessionsUpdated unique");
+      assert.false(sessionsUpdated.multiEntry, "sessionsUpdated multiEntry");
+    });
   });
 }