diff --git a/lib/import/import_container.dart b/lib/import/import_container.dart
index 8075847b4..234564fdc 100644
--- a/lib/import/import_container.dart
+++ b/lib/import/import_container.dart
@@ -32,6 +32,7 @@ import 'dart:typed_data';
 
 import 'package:archive/archive.dart';
 import 'package:path/path.dart' as p;
+import 'package:sqflite/sqflite.dart';
 
 /// What the first bytes of the picked file say it is.
 enum ImportContainer {
@@ -147,6 +148,68 @@ bool noopCsvFirstRecordMatches(String text, {bool truncated = false}) {
   return false;
 }
 
+/// True when [path] is a database THIS app wrote: an export, an auto-backup,
+/// or a quarantined copy — judged by CONTENT when the name does not say so.
+///
+/// The router used to go by name alone (`.db`, `.db.gz`, `.db.unopenable-`).
+/// A backup that came back off Drive, a mail attachment or a file manager
+/// under any other name is still a SQLite file, so it fell through to
+/// [isNoopExport], which claims every SQLite file, and the user restoring
+/// their own history was told "That database is not a NOOP backup" (#606).
+/// `LocalDb.importFromDbFile` already reads by magic bytes for the same
+/// reason; this makes the router agree with it.
+///
+/// A name that says it is ours is still believed without opening the file, so
+/// a damaged backup reaches the backup importer and gets ITS message.
+///
+/// Null means the inspection itself failed (the file would not open or
+/// query), which is not the same as "not ours": the caller must not hand it to
+/// [isNoopExport], which claims every SQLite file.
+Future<bool?> isEdgeBackup(String path) async {
+  final lower = path.toLowerCase();
+  if (lower.endsWith('.db') ||
+      lower.endsWith('.db.gz') ||
+      lower.contains('.db.unopenable-')) {
+    return true;
+  }
+  // Never throws: this runs while a decrypted backup may be sitting in the
+  // temp directory, before the caller's cleanup is armed. An unreadable file
+  // is reported as null, and the caller shows the generic unreadable-file path.
+  ResolvedNoopDatabase? resolved;
+  try {
+    final kind = await sniffFile(path);
+    if (kind != ImportContainer.sqlite && kind != ImportContainer.gzip) {
+      return false;
+    }
+    // Unwraps the gzip; null when it does not hold a database.
+    resolved = await resolveNoopDatabase(path);
+    if (resolved == null) return false;
+    final src = await openDatabase(resolved.path,
+        readOnly: true, singleInstance: false);
+    try {
+      final tables = {
+        for (final r in await src
+            .rawQuery("SELECT name FROM sqlite_master WHERE type = 'table'"))
+          r['name'],
+      };
+      // `hrSample` is NOOP's spine. Ours is the raw ledger, the baselines and
+      // a per-day result table TOGETHER: one generic name such as `samples`
+      // in somebody else's database must not get its rows merged into the
+      // user's history.
+      return !tables.contains('hrSample') &&
+          tables.contains('samples') &&
+          tables.contains('baselines') &&
+          (tables.contains('day_result') || tables.contains('derived_day'));
+    } finally {
+      await src.close();
+    }
+  } catch (_) {
+    return null;
+  } finally {
+    await resolved?.dispose();
+  }
+}
+
 /// True when [path] is a NOOP export — judged by CONTENT, not by name.
 ///
 /// The onboarding router used to switch on the extension: `.noopbak`/`.zip`
diff --git a/lib/ui2/onboarding/welcome.dart b/lib/ui2/onboarding/welcome.dart
index e290466d8..c37a90ed7 100644
--- a/lib/ui2/onboarding/welcome.dart
+++ b/lib/ui2/onboarding/welcome.dart
@@ -411,21 +411,33 @@ Future<ImportOutcome> runImport(
   // multi-select and this used to return inside the winning branch, so a
   // backup selected alongside a vendor CSV imported the backup and threw the
   // CSV away without a word.
-  final db = [...plain.where(_isDbBackup), ...decrypted];
+  final ownDb = <String>{};
   // Raw-vs-vendor is decided by what the file HOLDS, not by what it is called.
   // See [isNoopExport]: routing on the extension sent NOOP's raw-sensor `.csv`
   // to the vendor importer and WHOOP's `.zip` to the NOOP one — both files
   // fine, both refused, both with advice for the other file.
   final raw = <String>[];
   final csv = <String>[];
-  for (final p in plain) {
-    if (_isDbBackup(p)) continue;
-    (await isNoopExport(p) ? raw : csv).add(p);
-  }
+  final db = <String>[];
 
   if (decrypted.isNotEmpty) sources.add('Encrypted backup');
-  if (plain.any(_isDbBackup)) sources.add('OpenStrap backup');
   try {
+    // Inside the cleanup boundary: a throw while sniffing must not leave a
+    // decrypted backup in the temp directory.
+    for (final p in plain) {
+      final own = await isEdgeBackup(p);
+      if (own == true) {
+        ownDb.add(p);
+      } else if (own == null) {
+        // Inspection failed: not claimable as ours, and not a NOOP export
+        // either, so the vendor path's generic message is the honest one.
+        csv.add(p);
+      } else {
+        (await isNoopExport(p) ? raw : csv).add(p);
+      }
+    }
+    if (ownDb.isNotEmpty) sources.add('OpenStrap backup');
+    db.addAll([...plain.where(ownDb.contains), ...decrypted]);
     for (final p in db) {
       days += await app.importEdgeBackup(p);
       // The rows are in and the rollup rebuild threw. AppState's own note:
@@ -470,7 +482,13 @@ Future<ImportOutcome> runImport(
     // comes back as `FileSystemException: Failed to decode data using encoding
     // 'utf-8'`, which no catch below was going to turn into advice. The vendor
     // path unwraps archives (and gzip) properly, so hand them straight over.
-    if (await sniffFile(p) != ImportContainer.text) {
+    // An unreadable file is the vendor path's to report (it is caught below
+    // and named); throwing here would lose the counts already landed.
+    ImportContainer? kind;
+    try {
+      kind = await sniffFile(p);
+    } catch (_) {}
+    if (kind != ImportContainer.text) {
       vendor.add(p);
       continue;
     }
@@ -624,19 +642,6 @@ Future<String> decryptToTemp(String path, String passphrase) async {
   return dest;
 }
 
-bool _isDbBackup(String path) {
-  final p = path.toLowerCase();
-  // `.db.unopenable-<ms>` is what a corrupt-database rebuild quarantines the
-  // old file as, and the rebuilt card points the user straight at it. Matching
-  // only the `.db` suffix handed that SQLite file to the vendor-CSV importer.
-  // `.db.gz` is what the app's own automatic backup writes (auto_backup.dart's
-  // kBackupExtension). Leaving it out sent a user restoring their own backup
-  // down the vendor-CSV path, which is the one import that has to work.
-  return p.endsWith('.db') ||
-      p.endsWith('.db.gz') ||
-      p.contains('.db.unopenable-');
-}
-
 class WelcomeView extends StatelessWidget {
   final bool busy;
   final ImportOutcome? outcome;
diff --git a/test/import_routing_test.dart b/test/import_routing_test.dart
index 69194a107..fae092f97 100644
--- a/test/import_routing_test.dart
+++ b/test/import_routing_test.dart
@@ -17,6 +17,8 @@ import 'dart:io';
 
 import 'package:archive/archive.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:sqflite_common_ffi/sqflite_ffi.dart';
+import 'package:openstrap_edge/import/import_container.dart';
 import 'package:openstrap_edge/state/app_state.dart';
 import 'package:openstrap_edge/ui2/onboarding/welcome.dart';
 
@@ -28,6 +30,13 @@ class _RoutingSpy extends AppState {
 
   final noop = <String>[];
   final vendor = <String>[];
+  final backup = <String>[];
+
+  @override
+  Future<int> importEdgeBackup(String path) async {
+    backup.add(path);
+    return 1;
+  }
 
   @override
   Future<int> importNoopCsv(String path,
@@ -146,6 +155,112 @@ void main() {
     expect(app.vendor, isEmpty);
   });
 
+  // #606: the app's own backup, renamed on its way through Drive or a file
+  // manager, was a SQLite file the NOOP path claimed: "That database is not a
+  // NOOP backup — it has no `hrSample` table".
+  group('own backup by content', () {
+    setUpAll(() {
+      sqfliteFfiInit();
+      databaseFactory = databaseFactoryFfi;
+    });
+
+    Future<String> sqlite(String name, List<String> tables) async {
+      final path = '${tmp.path}/$name';
+      final db = await openDatabase(path, singleInstance: false);
+      for (final t in tables) {
+        await db.execute('CREATE TABLE $t (id INTEGER PRIMARY KEY)');
+      }
+      await db.close();
+      return path;
+    }
+
+    const ours = ['samples', 'baselines', 'day_result'];
+
+    test('a renamed backup goes to the backup importer', () async {
+      final app = _RoutingSpy();
+      final path = await sqlite('openstrap-backup (1)', ours);
+
+      final out = await runImport(app, [path]);
+
+      expect(app.backup, [path]);
+      expect(app.noop, isEmpty, reason: 'this is the #606 refusal');
+      expect(out.source, contains('OpenStrap backup'));
+    });
+
+    test('a renamed gzipped auto-backup goes to the backup importer',
+        () async {
+      final app = _RoutingSpy();
+      final plain = await sqlite('auto', ['samples', 'baselines', 'derived_day']);
+      final path = await write(
+          'backup-2026-10-18.gz', gzip.encode(File(plain).readAsBytesSync()));
+
+      await runImport(app, [path]);
+
+      expect(app.backup, [path]);
+      expect(app.noop, isEmpty);
+      expect(app.vendor, isEmpty);
+    });
+
+    test('a bare NOOP database still goes to the NOOP importer', () async {
+      final app = _RoutingSpy();
+      final path = await sqlite('noop-backup.sqlite', ['hrSample', ...ours]);
+
+      await runImport(app, [path]);
+
+      expect(app.noop, [path]);
+      expect(app.backup, isEmpty);
+    });
+
+    test('one generic table name does not make a database ours', () async {
+      final app = _RoutingSpy();
+      final path = await sqlite('someone-elses.sqlite', ['samples']);
+
+      await runImport(app, [path]);
+
+      expect(app.backup, isEmpty,
+          reason: 'its rows would be merged into the user\'s history');
+    });
+
+    test('a file that vanished reports a failed inspection, not a throw',
+        () async {
+      expect(await isEdgeBackup('${tmp.path}/gone.sqlite'), isNull);
+    });
+
+    test('a database that will not open is not sent to the NOOP importer',
+        () async {
+      final app = _RoutingSpy();
+      final path = await write('broken.sqlite',
+          [...utf8.encode('SQLite format 3\x00'), ...List.filled(200, 7)]);
+
+      await runImport(app, [path]);
+
+      expect(app.noop, isEmpty,
+          reason: 'the NOOP check claims every SQLite file');
+      expect(app.vendor, [path]);
+    });
+
+    test('a vanished file after a backup does not lose the backup counts',
+        () async {
+      final app = _RoutingSpy();
+      final good = await write('mine.db', utf8.encode('x'));
+
+      final out = await runImport(app, [good, '${tmp.path}/gone.bin']);
+
+      expect(app.backup, [good]);
+      expect(out.days, greaterThan(0));
+    });
+
+    test('a file named .db is still ours without being opened', () async {
+      final app = _RoutingSpy();
+      final path = await write('damaged.db', utf8.encode('not a database'));
+
+      await runImport(app, [path]);
+
+      expect(app.backup, [path],
+          reason: 'the backup importer owns the message for a damaged backup');
+    });
+  });
+
   test('a journal export re-saved as cp1252 is named, not handed to the '
       'vendor importer', () async {
     final app = _RoutingSpy();