diff --git a/CHANGELOG.md b/CHANGELOG.md
index b63e95f..47868a4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -32,7 +32,8 @@ Bugfix release for SFTP locations and large repositories. Tested on a production
 - Checking and opening a large repository over SFTP is much faster: the index files (one per
   pack, 27,547 for 1 TB) are downloaded 32 at a time instead of one after the other, 114 instead
   of 6 files per second to a Hetzner Storage Box (about 4 minutes instead of 77 for 1 TB). A check
-  also lists the pack folders (256 requests) instead of asking for every pack.
+  of a repository with more than 256 packs also lists the pack folders (256 requests) instead of
+  asking for every pack.
 - App store listing: the author's e-mail address is shown.
 - App store listing: the homepage link points to the GitHub repository instead of back to the
   app store page itself.
diff --git a/lib/Repository/BlobIndex.php b/lib/Repository/BlobIndex.php
index 632fa32..1fcfc3d 100644
--- a/lib/Repository/BlobIndex.php
+++ b/lib/Repository/BlobIndex.php
@@ -211,6 +211,15 @@ final class BlobIndex {
 		}
 	}
 
+	/** Number of packs that hold blobs of the index. */
+	public function packCount(): int {
+		$packs = [];
+		foreach ($this->blobs as [$pack]) {
+			$packs[$pack] = true;
+		}
+		return count($packs);
+	}
+
 	/** Bytes of all blobs in the index (encrypted size, i.e. what is stored in packs). */
 	public function storedBytes(): int {
 		$total = 0;
diff --git a/lib/Repository/Repository.php b/lib/Repository/Repository.php
index 5298596..188266c 100644
--- a/lib/Repository/Repository.php
+++ b/lib/Repository/Repository.php
@@ -37,6 +37,8 @@ final class Repository {
 	private ?int $maxBytes = null;
 	private Catalog $catalog;
 	private PackReader $packReader;
+	/** verify() lists the pack folders from this many packs on (see presentPacks()); tests lower it. */
+	public int $listPacksAbove = 256;
 
 	private function __construct(
 		private IBackend $backend,
@@ -803,7 +805,9 @@ final class Repository {
 	/**
 	 * Which packs are on the location, from one listing per pack folder instead of a request per
 	 * pack. A folder that cannot be listed, or comes back empty (which a storage also reports when
-	 * it could not look), is left out: its packs are then checked one by one.
+	 * it could not look), is left out: its packs are then checked one by one. With no more packs
+	 * than folders nothing is listed: a request per pack is fewer requests then, and on FTP every
+	 * request takes a data connection, of which a server may have only a few.
 	 *
 	 * @return array{0: array<string, bool>, 1: array<string, true>} pack id => present, and the
 	 *                                                              folders that were listed
@@ -811,6 +815,9 @@ final class Repository {
 	private function presentPacks(callable $heartbeat): array {
 		$present = [];
 		$listed = [];
+		if ($this->index->packCount() <= $this->listPacksAbove) {
+			return [$present, $listed];
+		}
 		for ($i = 0; $i < 256; $i++) {
 			$dir = sprintf('%02x', $i);
 			try {
diff --git a/tests/Unit/Repository/VerifyTest.php b/tests/Unit/Repository/VerifyTest.php
index c210739..480cd95 100644
--- a/tests/Unit/Repository/VerifyTest.php
+++ b/tests/Unit/Repository/VerifyTest.php
@@ -83,7 +83,9 @@ class VerifyTest extends TestCase {
 		$s = $repo->backupDirectory($this->src);
 		$seen = [];
 
-		$this->open()->verify($s['snapshot'], heartbeat: function (array $p) use (&$seen): void {
+		$open = $this->open();
+		$open->listPacksAbove = 0;
+		$open->verify($s['snapshot'], heartbeat: function (array $p) use (&$seen): void {
 			$seen[] = $p;
 		});
 
@@ -95,13 +97,32 @@ class VerifyTest extends TestCase {
 		$this->assertNull($last['total'], 'this snapshot has no file count in its metadata (a backup run records one)');
 	}
 
-	public function testVerifyListsPackFoldersInsteadOfCheckingEveryPack(): void {
+	/** Lists the pack folders however few packs there are. */
+	private static function listing(Repository $repo): Repository {
+		$repo->listPacksAbove = 0;
+		return $repo;
+	}
+
+	public function testWithNoMorePacksThanFoldersEveryPackIsCheckedInstead(): void {
+		// fewer requests; on FTP each takes a data connection, of which a server may have few
 		$repo = Repository::initWithKey($this->backend, $this->keys, $this->keys->wrap('pw'));
 		$s = $repo->backupDirectory($this->src);
 		$counting = new ListingBackend($this->backend);
 
 		$result = Repository::openWithKey($counting, $this->keys, null, null)->verify($s['snapshot']);
 
+		$this->assertSame([], $result['missing']);
+		$this->assertSame(0, $counting->packListings);
+		$this->assertGreaterThan(0, $counting->packExists);
+	}
+
+	public function testVerifyListsPackFoldersInsteadOfCheckingEveryPack(): void {
+		$repo = Repository::initWithKey($this->backend, $this->keys, $this->keys->wrap('pw'));
+		$s = $repo->backupDirectory($this->src);
+		$counting = new ListingBackend($this->backend);
+
+		$result = self::listing(Repository::openWithKey($counting, $this->keys, null, null))->verify($s['snapshot']);
+
 		$this->assertSame([], $result['missing']);
 		$this->assertSame(0, $counting->packExists);
 	}
@@ -111,7 +132,7 @@ class VerifyTest extends TestCase {
 		$s = $repo->backupDirectory($this->src);
 		$counting = new ListingBackend($this->backend, unlistable: true);
 
-		$result = Repository::openWithKey($counting, $this->keys, null, null)->verify($s['snapshot']);
+		$result = self::listing(Repository::openWithKey($counting, $this->keys, null, null))->verify($s['snapshot']);
 
 		$this->assertSame([], $result['missing']);
 		$this->assertGreaterThan(0, $counting->packExists);
@@ -123,7 +144,7 @@ class VerifyTest extends TestCase {
 		$s = $repo->backupDirectory($this->src);
 		$counting = new ListingBackend($this->backend, emptyListings: true);
 
-		$result = Repository::openWithKey($counting, $this->keys, null, null)->verify($s['snapshot']);
+		$result = self::listing(Repository::openWithKey($counting, $this->keys, null, null))->verify($s['snapshot']);
 
 		$this->assertSame([], $result['missing']);
 		$this->assertGreaterThan(0, $counting->packExists);
@@ -140,7 +161,7 @@ class VerifyTest extends TestCase {
 		}
 		$counting = new ListingBackend($this->backend);
 
-		$result = Repository::openWithKey($counting, $this->keys, null, null)->verify($s['snapshot']);
+		$result = self::listing(Repository::openWithKey($counting, $this->keys, null, null))->verify($s['snapshot']);
 
 		$this->assertNotSame([], $result['missing']);
 		$this->assertSame(0, $counting->packExists);
@@ -153,7 +174,7 @@ class VerifyTest extends TestCase {
 			$this->backend->delete($pack);
 		}
 
-		$result = Repository::openWithKey(new ListingBackend($this->backend), $this->keys, null, null)->verify($s['snapshot']);
+		$result = self::listing(Repository::openWithKey(new ListingBackend($this->backend), $this->keys, null, null))->verify($s['snapshot']);
 
 		$this->assertNotSame([], $result['missing']);
 	}
@@ -269,6 +290,7 @@ final class ListingBackend implements IBackend {
 	use \OCA\NgBackup\Backend\GetsOneByOne;
 
 	public int $packExists = 0;
+	public int $packListings = 0;
 
 	public function __construct(
 		private IBackend $inner,
@@ -305,6 +327,9 @@ final class ListingBackend implements IBackend {
 	}
 
 	public function listFiles(string $dir): array {
+		if (str_starts_with($dir, 'packs/')) {
+			$this->packListings++;
+		}
 		if ($this->unlistable && str_starts_with($dir, 'packs/')) {
 			throw new BackendException('Cannot list ' . $dir);
 		}