diff --git a/pkgs/applications/networking/mailreaders/thunderbird/default.nix b/pkgs/applications/networking/mailreaders/thunderbird/default.nix
index c98ba2d06ad..966e1886f34 100644
--- a/pkgs/applications/networking/mailreaders/thunderbird/default.nix
+++ b/pkgs/applications/networking/mailreaders/thunderbird/default.nix
@@ -72,7 +72,6 @@ in stdenv.mkDerivation rec {
       "--enable-system-sqlite"
       #"--enable-system-cairo"
       "--enable-startup-notification"
-      "--enable-content-sandbox"            # available since 26.0, but not much info available
       "--disable-crashreporter"
       "--disable-tests"
       "--disable-necko-wifi" # maybe we want to enable this at some point