diff --git a/org.mozilla.firefox.json b/org.mozilla.firefox.json
index 66128a9..ae976e3 100644
--- a/org.mozilla.firefox.json
+++ b/org.mozilla.firefox.json
@@ -57,6 +57,7 @@
             "title": "Preferences",
             "properties": {
                 "app.update.auto": {"type": "boolean", "title": "Enable Auto Update", "default": "true"},
+                "security.osclientcerts.autoload": {"type": "boolean", "title": "Use OS Client Certificates", "default": "false"},
                 "security.default_personal_cert": {"type": "string", "title": "Default Personal Certificate", "default": "Ask Every Time"}
                }
         },