diff --git a/components/ILIAS/Filesystem/src/Util/Archive/Zip.php b/components/ILIAS/Filesystem/src/Util/Archive/Zip.php
index 173f94ea7930..d712eef5d179 100755
--- a/components/ILIAS/Filesystem/src/Util/Archive/Zip.php
+++ b/components/ILIAS/Filesystem/src/Util/Archive/Zip.php
@@ -32,23 +32,24 @@ class Zip
     use PathHelper;
 
     public const DOT_EMPTY = '.empty';
+    public const ITERATION_FACTOR = 0.9;
     private string $zip_output_file = '';
     protected \ZipArchive $zip;
     private int $iteration_limit;
     private int $store_counter = 1;
     private int $path_counter = 1;
 
+    private bool $zip_opened = false;
+
     /**
      * @var FileStream[]
      */
-    private array $streams;
+    private array $streams = [];
 
     public function __construct(
         protected ZipOptions $options,
-        ...$streams
+        FileStream ...$streams
     ) {
-        $this->streams = array_filter($streams, fn($stream): bool => $stream instanceof FileStream);
-
         if ($options->getZipOutputPath() !== null && $options->getZipOutputName() !== null) {
             $this->zip_output_file = $this->ensureDirectorySeperator(
                 $options->getZipOutputPath()
@@ -70,7 +71,24 @@ public function __construct(
         if (!file_exists($this->zip_output_file)) {
             touch($this->zip_output_file);
         }
-        if ($this->zip->open($this->zip_output_file, \ZipArchive::OVERWRITE) !== true) {
+
+        $this->maybeOpenZip(\ZipArchive::OVERWRITE);
+        foreach ($streams as $path_inside_zip => $stream) {
+            $path_inside_zip = is_int($path_inside_zip) ? basename((string) $stream->getMetadata('uri')) : $path_inside_zip;
+            $this->addStream($stream, basename($path_inside_zip));
+        }
+    }
+
+    private function maybeOpenZip(int $flags = 0): void
+    {
+        if (!$this->zip_opened) {
+            if ($flags === 0) {
+                $this->zip_opened = $this->zip->open($this->zip_output_file) === true;
+            } else {
+                $this->zip_opened = $this->zip->open($this->zip_output_file, $flags) === true;
+            }
+        }
+        if (!$this->zip_opened) {
             throw new \Exception("cannot open <$this->zip_output_file>\n");
         }
     }
@@ -99,7 +117,7 @@ private function storeZIPtoFilesystem(): void
         foreach ($this->streams as $path_inside_zip => $stream) {
             $path = $stream->getMetadata('uri');
             if ($this->store_counter === 0) {
-                $this->zip->open($this->zip_output_file);
+                $this->maybeOpenZip();
             }
             if (is_int($path_inside_zip)) {
                 $path_inside_zip = basename((string) $path);
@@ -117,9 +135,10 @@ private function storeZIPtoFilesystem(): void
 
             if (
                 $this->store_counter === $this->iteration_limit
-                || count(get_resources('stream')) > ($this->iteration_limit * 0.9)
+                || count(get_resources('stream')) > ($this->iteration_limit * self::ITERATION_FACTOR)
             ) {
                 $this->zip->close();
+                $this->zip_opened = false;
                 $this->store_counter = 0;
             } else {
                 $this->store_counter++;
@@ -129,9 +148,11 @@ private function storeZIPtoFilesystem(): void
 
     public function get(): Stream
     {
+        $this->maybeOpenZip();
         $this->storeZIPtoFilesystem();
 
         $this->zip->close();
+        $this->zip_opened = false;
 
         return Streams::ofResource(fopen($this->zip_output_file, 'rb'));
     }
@@ -156,7 +177,9 @@ public function destroy(): void
      */
     public function addPath(string $path, ?string $path_inside_zip = null): void
     {
-        $path_inside_zip = $path_inside_zip ?? basename($path);
+        $path_inside_zip ??= basename($path);
+
+        $this->maybeOpenZip();
 
         // create directory if it does not exist
         $this->zip->addEmptyDir(rtrim(dirname($path_inside_zip), '/') . '/');
@@ -170,7 +193,7 @@ public function addPath(string $path, ?string $path_inside_zip = null): void
     public function addStream(FileStream $stream, string $path_inside_zip): void
     {
         // we remove the "empty zip file" now if possible
-        if (count($this->streams) === 1 && isset($this->streams[self::DOT_EMPTY])) {
+        if (isset($this->streams[self::DOT_EMPTY])) {
             unset($this->streams[self::DOT_EMPTY]);
         }
 
@@ -179,7 +202,7 @@ public function addStream(FileStream $stream, string $path_inside_zip): void
 
         if (
             $this->path_counter === $this->iteration_limit
-            || count(get_resources('stream')) > ($this->iteration_limit * 0.9)
+            || count(get_resources('stream')) > ($this->iteration_limit * self::ITERATION_FACTOR)
         ) {
             $this->storeZIPtoFilesystem();
             $this->streams = [];
@@ -225,7 +248,7 @@ public function addDirectory(string $directory_to_zip): void
             /** @var $file \SplFileInfo */
             if ($file->isDir()) {
                 // add directory to zip if it's empty
-                $sub_items = array_filter(scandir($pathname), static fn($d): bool => !str_contains((string) $d, '.DS_Store'));
+                $sub_items = array_filter(scandir($pathname), static fn($d): bool => !str_contains($d, '.DS_Store'));
                 if (count($sub_items) === 2) {
                     $this->zip->addEmptyDir($path_inside_zip);
                 }
diff --git a/components/ILIAS/Filesystem/tests/Util/ZipTest.php b/components/ILIAS/Filesystem/tests/Util/ZipTest.php
index 9a592d1b6b60..c910e4374bea 100755
--- a/components/ILIAS/Filesystem/tests/Util/ZipTest.php
+++ b/components/ILIAS/Filesystem/tests/Util/ZipTest.php
@@ -27,12 +27,12 @@
 use ILIAS\Filesystem\Util\Archive\ZipOptions;
 
 /**
- * @author Fabian Schmid <fabian@sr.solutions>
+ * @author                      Fabian Schmid <fabian@sr.solutions>
  *
  * @runTestsInSeparateProcesses // This is required for the test to work since we define some constants in the test
- * @preserveGlobalState    disabled
- * @backupGlobals          disabled
- * @backupStaticAttributes disabled
+ * @preserveGlobalState         disabled
+ * @backupGlobals               disabled
+ * @backupStaticAttributes      disabled
  */
 class ZipTest extends TestCase
 {
@@ -69,7 +69,39 @@ public function testZip(): void
         $this->assertGreaterThan(0, $zip_stream->getSize());
 
         $unzip_again = new Unzip(new UnzipOptions(), $zip_stream);
-        $this->assertEquals(2, $unzip_again->getAmountOfFiles());
+        $this->assertSame(2, $unzip_again->getAmountOfFiles());
+    }
+
+    public function testZip2(): void
+    {
+        $zip_options = new ZipOptions();
+        $streams = [
+            Streams::ofResource(fopen($this->zips_dir . '1_folder_1_file_mac.zip', 'r')),
+        ];
+        $zip = new Zip($zip_options, ...$streams);
+        $zip_stream = $zip->get();
+        $this->assertGreaterThan(0, $zip_stream->getSize());
+
+        $unzip_again = new Unzip(new UnzipOptions(), $zip_stream);
+        $this->assertSame(1, $unzip_again->getAmountOfFiles());
+    }
+
+    public function testZip3(): void
+    {
+        $zip_options = new ZipOptions();
+        $streams = [
+            Streams::ofResource(fopen($this->zips_dir . '1_folder_1_file_mac.zip', 'r')),
+            Streams::ofResource(fopen($this->zips_dir . '1_folder_mac.zip', 'r')),
+            Streams::ofResource(fopen($this->zips_dir . '1_folder_win.zip', 'r')),
+            Streams::ofResource(fopen($this->zips_dir . '3_folders_mac.zip', 'r')),
+            Streams::ofResource(fopen($this->zips_dir . '3_folders_win.zip', 'r')),
+        ];
+        $zip = new Zip($zip_options, ...$streams);
+        $zip_stream = $zip->get();
+        $this->assertGreaterThan(0, $zip_stream->getSize());
+
+        $unzip_again = new Unzip(new UnzipOptions(), $zip_stream);
+        $this->assertSame(5, $unzip_again->getAmountOfFiles());
     }
 
     public function testLegacyZip(): void
@@ -85,8 +117,19 @@ public function testLegacyZip(): void
         $legacy->zip($this->zips_dir, $this->unzips_dir . self::ZIPPED_ZIP, false);
         $this->assertFileExists($this->unzips_dir . self::ZIPPED_ZIP);
 
-        $unzip_again = new Unzip(new UnzipOptions(), Streams::ofResource(fopen($this->unzips_dir . self::ZIPPED_ZIP, 'r')));
-        $this->assertEquals(5, $unzip_again->getAmountOfFiles());
+        $unzip_again = new Unzip(
+            new UnzipOptions(),
+            Streams::ofResource(fopen($this->unzips_dir . self::ZIPPED_ZIP, 'r'))
+        );
+        $this->assertSame([
+            0 => './',
+            1 => '3_folders_win.zip',
+            2 => '1_folder_mac.zip',
+            3 => '3_folders_mac.zip',
+            4 => '1_folder_win.zip',
+            5 => '1_folder_1_file_mac.zip'
+        ], iterator_to_array($unzip_again->getPaths()));
+        $this->assertSame(5, $unzip_again->getAmountOfFiles());
 
         $depth = 0;
         foreach ($unzip_again->getPaths() as $path) {
@@ -111,8 +154,11 @@ public function LegacyZipWithTop(): void
         $legacy->zip($this->zips_dir, $this->unzips_dir . self::ZIPPED_ZIP, true);
         $this->assertFileExists($this->unzips_dir . self::ZIPPED_ZIP);
 
-        $unzip_again = new Unzip(new UnzipOptions(), Streams::ofResource(fopen($this->unzips_dir . self::ZIPPED_ZIP, 'r')));
-        $this->assertEquals(5, $unzip_again->getAmountOfFiles());
+        $unzip_again = new Unzip(
+            new UnzipOptions(),
+            Streams::ofResource(fopen($this->unzips_dir . self::ZIPPED_ZIP, 'r'))
+        );
+        $this->assertSame(5, $unzip_again->getAmountOfFiles());
 
         $depth = 0;
         foreach ($unzip_again->getPaths() as $path) {
@@ -145,10 +191,10 @@ public function testUnzip(
         $unzip = new Unzip($options, $stream);
 
         $this->assertFalse($unzip->hasZipReadingError());
-        $this->assertEquals($has_multiple_root_entries, $unzip->hasMultipleRootEntriesInZip());
-        $this->assertEquals($expected_amount_directories, $unzip->getAmountOfDirectories());
+        $this->assertSame($has_multiple_root_entries, $unzip->hasMultipleRootEntriesInZip());
+        $this->assertSame($expected_amount_directories, $unzip->getAmountOfDirectories());
         $this->assertEquals($expected_directories, iterator_to_array($unzip->getDirectories()));
-        $this->assertEquals($expected_amount_files, $unzip->getAmountOfFiles());
+        $this->assertSame($expected_amount_files, $unzip->getAmountOfFiles());
         $this->assertEquals($expected_files, iterator_to_array($unzip->getFiles()));
     }
 
@@ -159,14 +205,13 @@ public function testWrongZip(): void
         $unzip = new Unzip($options, $stream);
         $this->assertTrue($unzip->hasZipReadingError());
         $this->assertFalse($unzip->hasMultipleRootEntriesInZip());
-        $this->assertEquals(0, iterator_count($unzip->getFiles()));
-        $this->assertEquals(0, iterator_count($unzip->getDirectories()));
-        $this->assertEquals(0, iterator_count($unzip->getPaths()));
-        $this->assertEquals([], iterator_to_array($unzip->getDirectories()));
-        $this->assertEquals([], iterator_to_array($unzip->getFiles()));
+        $this->assertCount(0, iterator_to_array($unzip->getFiles()));
+        $this->assertCount(0, iterator_to_array($unzip->getDirectories()));
+        $this->assertCount(0, iterator_to_array($unzip->getPaths()));
+        $this->assertSame([], iterator_to_array($unzip->getDirectories()));
+        $this->assertSame([], iterator_to_array($unzip->getFiles()));
     }
 
-
     public function testLargeZIPs(): void
     {
         // get ulimit
@@ -264,15 +309,13 @@ private function directoryToArray(string $path_to_directory): array
 
     // PROVIDERS
 
-    public static function getZips(): array
+    public static function getZips(): \Iterator
     {
-        return [
-            ['1_folder_mac.zip', false, 10, self::$directories_one, 15, self::$files_one],
-            ['1_folder_win.zip', false, 10, self::$directories_one, 15, self::$files_one],
-            ['3_folders_mac.zip', true, 9, self::$directories_three, 12, self::$files_three],
-            ['3_folders_win.zip', true, 9, self::$directories_three, 12, self::$files_three],
-            ['1_folder_1_file_mac.zip', true, 3, self::$directories_mixed, 5, self::$files_mixed]
-        ];
+        yield ['1_folder_mac.zip', false, 10, self::$directories_one, 15, self::$files_one];
+        yield ['1_folder_win.zip', false, 10, self::$directories_one, 15, self::$files_one];
+        yield ['3_folders_mac.zip', true, 9, self::$directories_three, 12, self::$files_three];
+        yield ['3_folders_win.zip', true, 9, self::$directories_three, 12, self::$files_three];
+        yield ['1_folder_1_file_mac.zip', true, 3, self::$directories_mixed, 5, self::$files_mixed];
     }
 
     protected static array $files_mixed = [