diff --git a/CHANGELOG.md b/CHANGELOG.md
index a5140744..8f21798d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -31,6 +31,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 * `Slider` and `DragValue` uses fewer decimals by default. See the full precision by hovering over the value.
 * `egui::App`: added `fn name(&self)` and `fn clear_color(&self)`.
 * Combo boxes has scroll bars when needed.
+* Expand `Window` + `Resize` containers to be large enough for last frames content
 * `ui.columns`: Columns now defaults to justified top-to-down layouts.
 
 ### Fixed 🐛
diff --git a/egui/src/containers/resize.rs b/egui/src/containers/resize.rs
index 9acb7067..4a5f4591 100644
--- a/egui/src/containers/resize.rs
+++ b/egui/src/containers/resize.rs
@@ -182,6 +182,8 @@ impl Resize {
             .at_least(self.min_size)
             .at_most(self.max_size);
 
+        let mut user_requested_size = state.requested_size.take();
+
         let corner_response = if self.resizable {
             // Resize-corner:
             let corner_size = Vec2::splat(ui.style().visuals.resize_corner_size);
@@ -191,7 +193,8 @@ impl Resize {
 
             if corner_response.active {
                 if let Some(mouse_pos) = ui.input().mouse.pos {
-                    state.desired_size = mouse_pos - position + 0.5 * corner_response.rect.size();
+                    user_requested_size =
+                        Some(mouse_pos - position + 0.5 * corner_response.rect.size());
                 }
             }
             Some(corner_response)
@@ -199,9 +202,15 @@ impl Resize {
             None
         };
 
-        if let Some(requested_size) = state.requested_size.take() {
-            state.desired_size = requested_size;
+        if let Some(user_requested_size) = user_requested_size {
+            state.desired_size = user_requested_size;
+        } else {
+            // We are not being actively resized, so auto-expand to include size of last frame.
+            // This prevents auto-shrinking if the contents contain width-filling widgets (separators etc)
+            // but it makes a lot of interactions with `Window`s nicer.
+            state.desired_size = state.desired_size.max(state.last_content_size);
         }
+
         state.desired_size = state
             .desired_size
             .at_least(self.min_size)
@@ -269,11 +278,6 @@ impl Resize {
             ui.allocate_space(state.last_content_size);
         }
 
-        if ui.memory().resize.get(&id).is_none() {
-            // First frame.
-            state.desired_size = state.desired_size.at_least(state.last_content_size);
-        }
-
         // ------------------------------
 
         if self.with_stroke && corner_response.is_some() {