diff --git a/components/config/prefs.rs b/components/config/prefs.rs
index 65d7b987253..9e2c161a32c 100644
--- a/components/config/prefs.rs
+++ b/components/config/prefs.rs
@@ -238,6 +238,7 @@ mod gen {
                         enabled: bool,
                     }
                 },
+                allow_scripts_to_close_windows: bool,
                 canvas_capture: {
                     enabled: bool,
                 },
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index 08e1d5edf4f..5e7e1f8988c 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -60,6 +60,7 @@ use script_traits::{
 use selectors::attr::CaseSensitivity;
 use servo_arc::Arc as ServoArc;
 use servo_atoms::Atom;
+use servo_config::pref;
 use servo_geometry::{f32_rect_to_au_rect, MaxRect};
 use servo_url::{ImmutableOrigin, MutableOrigin, ServoUrl};
 use style::dom::OpaqueNode;
@@ -757,7 +758,9 @@ impl WindowMethods for Window {
             let is_auxiliary = window_proxy.is_auxiliary();
 
             // https://html.spec.whatwg.org/multipage/#script-closable
-            let is_script_closable = (self.is_top_level() && history_length == 1) || is_auxiliary;
+            let is_script_closable = (self.is_top_level() && history_length == 1) ||
+                is_auxiliary ||
+                pref!(dom.allow_scripts_to_close_windows);
 
             // TODO: rest of Step 3:
             // Is the incumbent settings object's responsible browsing context familiar with current?
diff --git a/resources/prefs.json b/resources/prefs.json
index 5f6d2f1fd16..bbef61ef194 100644
--- a/resources/prefs.json
+++ b/resources/prefs.json
@@ -1,6 +1,7 @@
 {
   "devtools.server.enabled": false,
   "devtools.server.port": 0,
+  "dom.allow_scripts_to_close_windows": false,
   "dom.bluetooth.enabled": false,
   "dom.bluetooth.testing.enabled": false,
   "dom.canvas_capture.enabled": false,