diff --git a/appendices/filters.xml b/appendices/filters.xml
index 1d11236e21..a95f442d92 100644
--- a/appendices/filters.xml
+++ b/appendices/filters.xml
@@ -521,7 +521,7 @@ $key = substr(md5('pass1'.$passphrase, true) .
 $opts = array('iv'=>$iv, 'key'=>$key);
 
 $fp = fopen('secert-file.enc', 'rb');
-stream_filter_append($fp, 'mdecrypt.tripledes', STREAM_FILTER_WRITE, $opts);
+stream_filter_append($fp, 'mdecrypt.tripledes', STREAM_FILTER_READ, $opts);
 $data = rtrim(stream_get_contents($fp));
 fclose($fp);