diff --git a/system/HTTP/ResponseTrait.php b/system/HTTP/ResponseTrait.php
index 3063e44116fb..265a62fb0a1f 100644
--- a/system/HTTP/ResponseTrait.php
+++ b/system/HTTP/ResponseTrait.php
@@ -733,20 +733,15 @@ public function download(string $filename = '', $data = '', bool $setMime = fals
             return null;
         }
 
-        $filepath = '';
         if ($data === null) {
-            $filepath = $filename;
-            $filename = explode('/', str_replace(DIRECTORY_SEPARATOR, '/', $filename));
-            $filename = end($filename);
+            $response = new DownloadResponse(basename($filename), $setMime);
+            $response->setFilePath($filename);
+
+            return $response;
         }
 
         $response = new DownloadResponse($filename, $setMime);
-
-        if ($filepath !== '') {
-            $response->setFilePath($filepath);
-        } elseif ($data !== null) {
-            $response->setBinary($data);
-        }
+        $response->setBinary($data);
 
         return $response;
     }
diff --git a/tests/system/HTTP/ResponseTest.php b/tests/system/HTTP/ResponseTest.php
index 38c349117cbb..8eb0432bd31d 100644
--- a/tests/system/HTTP/ResponseTest.php
+++ b/tests/system/HTTP/ResponseTest.php
@@ -494,6 +494,38 @@ public function testGetDownloadResponseByFilePath(): void
         $this->assertSame(file_get_contents(__FILE__), $actualOutput);
     }
 
+    public function testGetDownloadResponseByExtremeFilePath(): void
+    {
+        $response = new Response(new App());
+
+        $tempDir = sys_get_temp_dir() . DIRECTORY_SEPARATOR . 'ci4_test_dir';
+        @mkdir($tempDir);
+        $extremeName = 'my_extreme_file_!@#$%.txt';
+        $extremePath = $tempDir . DIRECTORY_SEPARATOR . $extremeName;
+        file_put_contents($extremePath, 'extreme data');
+
+        $actual = $response->download($extremePath, null);
+
+        $this->assertInstanceOf(DownloadResponse::class, $actual);
+        $actual->buildHeaders();
+
+        $expectedBasename = basename($extremePath);
+        $this->assertSame(
+            'attachment; filename="' . addslashes($expectedBasename) . '"; filename*=UTF-8\'\'' . rawurlencode($expectedBasename),
+            $actual->getHeaderLine('Content-Disposition'),
+        );
+
+        ob_start();
+        $actual->sendBody();
+        $actualOutput = ob_get_contents();
+        ob_end_clean();
+
+        $this->assertSame('extreme data', $actualOutput);
+
+        unlink($extremePath);
+        rmdir($tempDir);
+    }
+
     public function testVagueDownload(): void
     {
         $response = new Response(new App());