diff --git a/crates/egui_kittest/README.md b/crates/egui_kittest/README.md
index 2ffda785c05..04a07842382 100644
--- a/crates/egui_kittest/README.md
+++ b/crates/egui_kittest/README.md
@@ -12,13 +12,11 @@ use std::cell::RefCell;
 
 fn main() {
     let mut checked = false;
-    let app = |ctx: &Context| {
-        CentralPanel::default().show(ctx, |ui| {
-            ui.checkbox(&mut checked, "Check me!");
-        });
+    let app = |ui: &mut egui::Ui| {
+        ui.checkbox(&mut checked, "Check me!");
     };
 
-    let mut harness = Harness::builder().with_size(egui::Vec2::new(200.0, 100.0)).build(app);
+    let mut harness = Harness::new_ui(app);
     
     let checkbox = harness.get_by_label("Check me!");
     assert_eq!(checkbox.toggled(), Some(Toggled::False));
@@ -28,6 +26,9 @@ fn main() {
 
     let checkbox = harness.get_by_label("Check me!");
     assert_eq!(checkbox.toggled(), Some(Toggled::True));
+    
+    // Shrink the window size to the smallest size possible
+    harness.fit_contents();
 
     // You can even render the ui and do image snapshot tests
     #[cfg(all(feature = "wgpu", feature = "snapshot"))]
diff --git a/crates/egui_kittest/tests/snapshots/readme_example.png b/crates/egui_kittest/tests/snapshots/readme_example.png
index 66b21e7f4bf..ef0774162da 100644
--- a/crates/egui_kittest/tests/snapshots/readme_example.png
+++ b/crates/egui_kittest/tests/snapshots/readme_example.png
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:36c1b432140456ea5cbb687076b1c910aea8b31affd33a0ece22218f60af2d6e
-size 2296
+oid sha256:31bd906040fcc356c19dc36036fbfd2a28dfcef54c7a073f584f4a9abddbdb4c
+size 1699