diff --git a/tst/Data/FilesystemTest.php b/tst/Data/FilesystemTest.php
index e7e6dc82..e5b82640 100644
--- a/tst/Data/FilesystemTest.php
+++ b/tst/Data/FilesystemTest.php
@@ -130,4 +130,46 @@ class FilesystemTest extends PHPUnit_Framework_TestCase
         $this->assertFalse($this->_model->createComment(Helper::getPasteId(), Helper::getPasteId(), Helper::getCommentId(), $comment), 'unable to store broken comment');
         $this->assertFalse($this->_model->existsComment(Helper::getPasteId(), Helper::getPasteId(), Helper::getCommentId()), 'comment does still not exist');
     }
+
+    public function testOldFilesGetConverted()
+    {
+        // generate 10 (default purge batch size) pastes in the old format
+        $paste = Helper::getPaste();
+        $comment = Helper::getComment();
+        $commentid = Helper::getCommentId();
+        $ids = array();
+        for ($i = 0, $max = 10; $i < $max; ++$i) {
+            // PHPs mt_rand only supports 32 bit or up 0x7fffffff on 64 bit systems to be precise :-/
+            $dataid = str_pad(dechex(mt_rand(0, mt_getrandmax())), 8, '0', STR_PAD_LEFT) .
+                str_pad(dechex(mt_rand(0, mt_getrandmax())), 8, '0', STR_PAD_LEFT);
+            $storagedir = $this->_path . DIRECTORY_SEPARATOR  . substr($dataid, 0, 2) .
+                DIRECTORY_SEPARATOR . substr($dataid, 2, 2) . DIRECTORY_SEPARATOR;
+            $ids[$dataid] = $storagedir;
+
+            if (!is_dir($storagedir)) {
+                mkdir($storagedir, 0700, true);
+            }
+            file_put_contents($storagedir . $dataid, json_encode($paste));
+
+            $storagedir .= $dataid . '.discussion' . DIRECTORY_SEPARATOR;
+            if (!is_dir($storagedir)) {
+                mkdir($storagedir, 0700, true);
+            }
+            file_put_contents($storagedir . $dataid . '.' . $commentid . '.' . $dataid, json_encode($comment));
+        }
+        // check that all 10 pastes were converted after the purge
+        $this->_model->purge(10);
+        foreach ($ids as $dataid => $storagedir) {
+            $this->assertFileExists($storagedir . $dataid . '.php', "paste $dataid exists in new format");
+            $this->assertFileNotExists($storagedir . $dataid, "old format paste $dataid got removed");
+            $this->assertTrue($this->_model->exists($dataid), "paste $dataid exists");
+            $this->assertEquals($this->_model->read($dataid), $paste, "paste $dataid wasn't modified in the conversion");
+
+            $storagedir .= $dataid . '.discussion' . DIRECTORY_SEPARATOR;
+            $this->assertFileExists($storagedir . $dataid . '.' . $commentid . '.' . $dataid . '.php', "comment of $dataid exists in new format");
+            $this->assertFileNotExists($storagedir . $dataid . '.' . $commentid . '.' . $dataid, "old format comment of $dataid got removed");
+            $this->assertTrue($this->_model->existsComment($dataid, $dataid, $commentid), "comment in paste $dataid exists");
+            $this->assertEquals($this->_model->readComment($dataid, $dataid, $commentid), $comment, "comment of $dataid wasn't modified in the conversion");
+        }
+    }
 }