diff --git a/ports/servoshell/desktop/app_state.rs b/ports/servoshell/desktop/app_state.rs
index 5bd5ef42fb8..380b2435aca 100644
--- a/ports/servoshell/desktop/app_state.rs
+++ b/ports/servoshell/desktop/app_state.rs
@@ -444,11 +444,11 @@ impl WebViewDelegate for RunningAppState {
         self.inner().window.set_position(new_position);
     }
 
-    fn request_resize_to(&self, webview: servo::WebView, new_size: DeviceIntSize) {
+    fn request_resize_to(&self, webview: servo::WebView, new_outer_size: DeviceIntSize) {
         let mut rect = webview.rect();
-        rect.set_size(new_size.to_f32());
+        rect.set_size(new_outer_size.to_f32());
         webview.move_resize(rect);
-        self.inner().window.request_resize(&webview, new_size);
+        self.inner().window.request_resize(&webview, new_outer_size);
     }
 
     fn show_simple_dialog(&self, webview: servo::WebView, dialog: SimpleDialog) {
diff --git a/ports/servoshell/desktop/headed_window.rs b/ports/servoshell/desktop/headed_window.rs
index 341b8c12e67..e0d3124e804 100644
--- a/ports/servoshell/desktop/headed_window.rs
+++ b/ports/servoshell/desktop/headed_window.rs
@@ -466,14 +466,13 @@ impl WindowPortsMethods for Window {
         self.winit_window.set_title(title);
     }
 
-    fn request_resize(&self, _: &WebView, size: DeviceIntSize) -> Option<DeviceIntSize> {
-        let toolbar_height = self.toolbar_height() * self.hidpi_scale_factor();
-        let toolbar_height = toolbar_height.get().ceil() as i32;
-        let total_size = PhysicalSize::new(size.width, size.height + toolbar_height);
+    fn request_resize(&self, _: &WebView, new_outer_size: DeviceIntSize) -> Option<DeviceIntSize> {
+        let title_height =
+            self.winit_window.outer_size().height - self.winit_window.inner_size().height;
         self.winit_window
             .request_inner_size::<PhysicalSize<i32>>(PhysicalSize::new(
-                total_size.width,
-                total_size.height,
+                new_outer_size.width,
+                new_outer_size.height - title_height as i32,
             ))
             .and_then(|size| {
                 Some(DeviceIntSize::new(
diff --git a/ports/servoshell/desktop/window_trait.rs b/ports/servoshell/desktop/window_trait.rs
index 233c90cb5a5..1ef83443adf 100644
--- a/ports/servoshell/desktop/window_trait.rs
+++ b/ports/servoshell/desktop/window_trait.rs
@@ -26,8 +26,9 @@ pub trait WindowPortsMethods {
     fn get_fullscreen(&self) -> bool;
     fn handle_winit_event(&self, state: Rc<RunningAppState>, event: winit::event::WindowEvent);
     fn set_title(&self, _title: &str) {}
-    /// Request a new inner size for the window, not including external decorations.
-    fn request_resize(&self, webview: &WebView, inner_size: DeviceIntSize)
+    /// Request a new outer size for the window, including external decorations.
+    /// This should be the same as `window.outerWidth` and `window.outerHeight``
+    fn request_resize(&self, webview: &WebView, outer_size: DeviceIntSize)
     -> Option<DeviceIntSize>;
     fn set_position(&self, _point: DeviceIntPoint) {}
     fn set_fullscreen(&self, _state: bool) {}