diff --git a/lib/loofah/html5/safelist.rb b/lib/loofah/html5/safelist.rb
index fe17913..ae194fe 100644
--- a/lib/loofah/html5/safelist.rb
+++ b/lib/loofah/html5/safelist.rb
@@ -982,6 +982,7 @@ module SafeList
                                        "callto",
                                        "data",
                                        "ed2k",
+                                       "fax",
                                        "feed",
                                        "ftp",
                                        "gopher",
@@ -990,6 +991,7 @@ module SafeList
                                        "irc",
                                        "line",
                                        "mailto",
+                                       "modem",
                                        "news",
                                        "nntp",
                                        "rsync",