diff --git a/app/src/ViewFunctions/ParentDir.php b/app/src/ViewFunctions/ParentDir.php
index a5019dd..a9d3abc 100644
--- a/app/src/ViewFunctions/ParentDir.php
+++ b/app/src/ViewFunctions/ParentDir.php
@@ -22,6 +22,6 @@ class ParentDir extends ViewFunction
             explode('/', $path)
         )->filter()->slice(0, -1)->implode('/');
 
-        return empty($parentDir) ? '' : sprintf('?dir=%s', $parentDir);
+        return empty($parentDir) ? '.' : sprintf('?dir=%s', $parentDir);
     }
 }
diff --git a/tests/ViewFunctions/ParentDirTest.php b/tests/ViewFunctions/ParentDirTest.php
index 2273f0f..be5cc5e 100644
--- a/tests/ViewFunctions/ParentDirTest.php
+++ b/tests/ViewFunctions/ParentDirTest.php
@@ -7,7 +7,21 @@ use Tests\TestCase;
 
 class ParentDirTest extends TestCase
 {
-    public function test_it_can_get_the_parent_directory_from_a_path(): void
+    public function test_it_can_get_the_parent_directory_when_one_level_deep(): void
+    {
+        $parentDir = new ParentDir($this->container, $this->config);
+
+        $this->assertEquals('.', $parentDir('foo'));
+    }
+
+    public function test_it_can_get_the_parent_directory_when_two_levels_deep(): void
+    {
+        $parentDir = new ParentDir($this->container, $this->config);
+
+        $this->assertEquals('?dir=foo', $parentDir('foo/bar'));
+    }
+
+    public function test_it_can_get_the_parent_directory_when_three_levels_deep(): void
     {
         $parentDir = new ParentDir($this->container, $this->config);