diff --git a/app/src/Factories/TwigFactory.php b/app/src/Factories/TwigFactory.php
index a5a9881..1ca5c66 100644
--- a/app/src/Factories/TwigFactory.php
+++ b/app/src/Factories/TwigFactory.php
@@ -19,7 +19,7 @@ class TwigFactory
         ViewFunctions\Config::class,
         ViewFunctions\Icon::class,
         ViewFunctions\Markdown::class,
-        ViewFunctions\ParentDir::class,
+        ViewFunctions\ParentUrl::class,
         ViewFunctions\SizeForHumans::class,
         ViewFunctions\Translate::class,
         ViewFunctions\Url::class,
diff --git a/app/src/ViewFunctions/ParentDir.php b/app/src/ViewFunctions/ParentDir.php
deleted file mode 100644
index 4d5524d..0000000
--- a/app/src/ViewFunctions/ParentDir.php
+++ /dev/null
@@ -1,26 +0,0 @@
-<?php
-
-namespace App\ViewFunctions;
-
-use App\Support\Str;
-
-class ParentDir extends ViewFunction
-{
-    /** @var string The function name */
-    protected $name = 'parent_dir';
-
-    /**
-     * Get the parent directory for a given path.
-     *
-     * @param string $path
-     *
-     * @return string
-     */
-    public function __invoke(string $path)
-    {
-        $parentDir = Str::explode($path, DIRECTORY_SEPARATOR)
-            ->filter()->slice(0, -1)->implode(DIRECTORY_SEPARATOR);
-
-        return empty($parentDir) ? '.' : sprintf('?dir=%s', $parentDir);
-    }
-}
diff --git a/app/src/ViewFunctions/ParentUrl.php b/app/src/ViewFunctions/ParentUrl.php
new file mode 100644
index 0000000..48ce4cc
--- /dev/null
+++ b/app/src/ViewFunctions/ParentUrl.php
@@ -0,0 +1,42 @@
+<?php
+
+namespace App\ViewFunctions;
+
+use App\Support\Str;
+
+class ParentUrl extends ViewFunction
+{
+    /** @var string The function name */
+    protected $name = 'parent_url';
+
+    /** @var string The directory separator */
+    protected $directorySeparator;
+
+    /**
+     * Create a new ParentUrl object.
+     *
+     * @param string $directorySeparator
+     */
+    public function __construct(string $directorySeparator = DIRECTORY_SEPARATOR)
+    {
+        $this->directorySeparator = $directorySeparator;
+    }
+
+    /**
+     * Get the parent directory for a given path.
+     *
+     * @param string $path
+     *
+     * @return string
+     */
+    public function __invoke(string $path)
+    {
+        $parentDir = Str::explode($path, $this->directorySeparator)->map(
+            function (string $segment): string {
+                return urlencode($segment);
+            }
+        )->filter()->slice(0, -1)->implode($this->directorySeparator);
+
+        return empty($parentDir) ? '.' : sprintf('?dir=%s', $parentDir);
+    }
+}
diff --git a/app/views/components/file.twig b/app/views/components/file.twig
index d8e8578..9ce450c 100644
--- a/app/views/components/file.twig
+++ b/app/views/components/file.twig
@@ -1,5 +1,5 @@
 <a
-    href="{{ parentDir ? parent_dir(path) : url(file.getPathname, 'dir') }}"
+    href="{{ parentDir ? parent_url(path) : url(file.getPathname, 'dir') }}"
     class="flex flex-col items-center rounded-lg font-mono group hover:bg-gray-200 hover:shadow"
 >
     <div class="flex justify-between items-center p-4 w-full">
diff --git a/tests/Factories/TwigFactoryTest.php b/tests/Factories/TwigFactoryTest.php
index 34b65b6..7eea3db 100644
--- a/tests/Factories/TwigFactoryTest.php
+++ b/tests/Factories/TwigFactoryTest.php
@@ -53,7 +53,7 @@ class TwigFactoryTest extends TestCase
         );
 
         $this->assertInstanceOf(
-            ViewFunctions\ParentDir::class,
+            ViewFunctions\ParentUrl::class,
             $twig->getEnvironment()->getFunction('parent_dir')->getCallable()
         );
 
diff --git a/tests/ViewFunctions/ParentDirTest.php b/tests/ViewFunctions/ParentUrlTest.php
similarity index 50%
rename from tests/ViewFunctions/ParentDirTest.php
rename to tests/ViewFunctions/ParentUrlTest.php
index 3c7c7f5..2671866 100644
--- a/tests/ViewFunctions/ParentDirTest.php
+++ b/tests/ViewFunctions/ParentUrlTest.php
@@ -2,28 +2,28 @@
 
 namespace Tests\ViewFunctions;
 
-use App\ViewFunctions\ParentDir;
+use App\ViewFunctions\ParentUrl;
 use Tests\TestCase;
 
-class ParentDirTest extends TestCase
+class ParentUrlTest extends TestCase
 {
     public function test_it_can_get_the_parent_directory_when_one_level_deep(): void
     {
-        $parentDir = new ParentDir;
+        $parentDir = new ParentUrl;
 
         $this->assertEquals('.', $parentDir('foo'));
     }
 
     public function test_it_can_get_the_parent_directory_when_two_levels_deep(): void
     {
-        $parentDir = new ParentDir;
+        $parentDir = new ParentUrl;
 
         $this->assertEquals('?dir=foo', $parentDir('foo/bar'));
     }
 
     public function test_it_can_get_the_parent_directory_when_three_levels_deep(): void
     {
-        $parentDir = new ParentDir;
+        $parentDir = new ParentUrl;
 
         $this->assertEquals('?dir=foo/bar', $parentDir('foo/bar/baz'));
     }
@@ -32,8 +32,24 @@ class ParentDirTest extends TestCase
     {
         $_SERVER['SCRIPT_NAME'] = '/some/dir/index.php';
 
-        $parentDir = new ParentDir;
+        $parentDir = new ParentUrl;
 
         $this->assertEquals('?dir=foo/bar', $parentDir('foo/bar/baz'));
     }
+
+    public function test_it_can_get_the_parent_directory_with_back_slashes(): void
+    {
+        $parentDir = new ParentUrl('\\');
+
+        $this->assertEquals('?dir=foo\bar', $parentDir('foo\bar\baz'));
+    }
+
+    public function test_parent_url_segments_are_url_encoded(): void
+    {
+        $parentDir = new ParentUrl;
+
+        $this->assertEquals('?dir=foo/bar%2Bbaz', $parentDir('foo/bar+baz/qux'));
+        $this->assertEquals('?dir=foo/bar%23baz', $parentDir('foo/bar#baz/qux'));
+        $this->assertEquals('?dir=foo/bar%26baz', $parentDir('foo/bar&baz/qux'));
+    }
 }