diff --git a/files/diskfree-tracker b/files/diskfree-tracker
index c98ed6a..2f8f78d 100755
--- a/files/diskfree-tracker
+++ b/files/diskfree-tracker
@@ -43,7 +43,7 @@ Shows the output of df in colour.
                         help="Refresh delay")
     parser.add_argument("-1",action="store_true",dest="once",default=False,
                         help="Run once and exit")
-    parser.add_argument("-x",'--exclude',type=str,dest="exclude",default="tmpfs,devtmpfs,squashfs",
+    parser.add_argument("-x",'--exclude',type=str,dest="exclude",default="tmpfs,devtmpfs,squashfs,overlay",
                         help="Comma separated list of excluded filesystem types. Defaults: %(default)s")
     parser.add_argument("--version",action='version', version=VERSION)
     options=parser.parse_args()