diff --git a/pkgs/tools/networking/isync/default.nix b/pkgs/tools/networking/isync/default.nix
index ccf32b438434..89b200e8e563 100644
--- a/pkgs/tools/networking/isync/default.nix
+++ b/pkgs/tools/networking/isync/default.nix
@@ -1,7 +1,9 @@
 { lib, stdenv, fetchurl, pkg-config, perl
 , openssl, db, cyrus_sasl, zlib
 , Security
-, withCyrusSaslXoauth2 ? true, cyrus-sasl-xoauth2, makeWrapper
+# Disabled by default as XOAUTH2 is an "OBSOLETE" SASL mechanism and this relies
+# on a package that isn't really maintained anymore:
+, withCyrusSaslXoauth2 ? false, cyrus-sasl-xoauth2, makeWrapper
 }:
 
 stdenv.mkDerivation rec {