diff --git a/index.php b/index.php
index 5604af3..a90e0b8 100755
--- a/index.php
+++ b/index.php
@@ -103,7 +103,7 @@ function storeFile($name, $tmpFile, $formatted = false)
         mkdir($STORE_PATH, 0750, true); //TODO: error handling
     }
 
-    $ext = pathinfo($name, PATHINFO_EXTENSION);
+    $ext = getExtension($name);
     $id = rndStr($ID_LENGTH);
     $basename = $id . '.' . $ext;
     $target_file = $STORE_PATH . $basename;
@@ -132,6 +132,18 @@ function storeFile($name, $tmpFile, $formatted = false)
     }
 }
 
+function getExtension($path)
+{
+    $ext = pathinfo($path, PATHINFO_EXTENSION);
+    //special handling of .tar.* archives
+    $ext2 = pathinfo(substr($path,0,-(strlen($ext)+1)), PATHINFO_EXTENSION);
+    if ($ext2 === 'tar')
+    {
+        $ext = $ext2.'.'.$ext;
+    }
+    return $ext;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // purge all files older than their retention period allows.
 ////////////////////////////////////////////////////////////////////////////////