diff --git a/inc/instance-config.php b/inc/instance-config.php
index ac5d75b5..16d5b7a0 100644
--- a/inc/instance-config.php
+++ b/inc/instance-config.php
@@ -154,8 +154,11 @@ $config['allowed_ext_files'][] = 'mp3';
 $config['allowed_ext_files'][] = 'mp4';
 $config['allowed_ext_files'][] = 'pdf';
 $config['allowed_ext_files'][] = 'txt';
-$config['allowed_ext_files'][] = 'zip';
 $config['allowed_ext_files'][] = 'epub';
+// Compressed files
+$config['allowed_ext_files'][] = 'zip';
+$config['allowed_ext_files'][] = 'gz';
+$config['allowed_ext_files'][] = 'bz2';
 
 /*
  * Flags