diff --git a/components/config/prefs.rs b/components/config/prefs.rs
index e8b8b9a1e7e..76e70933bde 100644
--- a/components/config/prefs.rs
+++ b/components/config/prefs.rs
@@ -222,6 +222,9 @@ mod gen {
                         enabled: bool,
                     }
                 },
+                shadowdom: {
+                    enabled: bool,
+                },
                 svg: {
                     enabled: bool,
                 },
diff --git a/resources/prefs.json b/resources/prefs.json
index 1ca4197be44..b882ad9ca46 100644
--- a/resources/prefs.json
+++ b/resources/prefs.json
@@ -19,6 +19,7 @@
   "dom.serviceworker.enabled": false,
   "dom.serviceworker.timeout_seconds": 60,
   "dom.servoparser.async_html_tokenizer.enabled": false,
+  "dom.shadowdom.enabled": false,
   "dom.svg.enabled": false,
   "dom.testable_crash.enabled": false,
   "dom.testbinding.enabled": false,