diff --git a/egui/src/app.rs b/egui/src/app.rs
index 4a4017e3..9d3c4cc0 100644
--- a/egui/src/app.rs
+++ b/egui/src/app.rs
@@ -38,6 +38,11 @@ pub trait App {
     /// Optional.
     fn setup(&mut self, _ctx: &crate::CtxRef) {}
 
+    /// Returns true if this app window should be resizable.
+    fn is_resizable(&self) -> bool {
+        true
+    }
+
     /// Called each time the UI needs repainting, which may be many times per second.
     /// Put your widgets into a `SidePanel`, `TopPanel`, `CentralPanel`, `Window` or `Area`.
     fn ui(&mut self, ctx: &crate::CtxRef, integration_context: &mut IntegrationContext<'_>);
diff --git a/egui_glium/CHANGELOG.md b/egui_glium/CHANGELOG.md
index 6d95c482..94943b18 100644
--- a/egui_glium/CHANGELOG.md
+++ b/egui_glium/CHANGELOG.md
@@ -10,6 +10,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Added
 
 * `egui_glium` will auto-save your app state every 30 seconds.
+* `egui_glium` can now set windows as fixed size (e.g. the user can't resize the window). See `egui::App::is_resizable()`.
 
 ### Changed
 
diff --git a/egui_glium/src/backend.rs b/egui_glium/src/backend.rs
index ed864d81..d722e246 100644
--- a/egui_glium/src/backend.rs
+++ b/egui_glium/src/backend.rs
@@ -42,11 +42,12 @@ impl egui::app::RepaintSignal for GliumRepaintSignal {
 fn create_display(
     title: &str,
     window_settings: Option<WindowSettings>,
+    is_resizable: bool,
     event_loop: &glutin::event_loop::EventLoop<RequestRepaintEvent>,
 ) -> glium::Display {
     let mut window_builder = glutin::window::WindowBuilder::new()
         .with_decorations(true)
-        .with_resizable(true)
+        .with_resizable(is_resizable)
         .with_title(title)
         .with_transparent(false);
 
@@ -102,7 +103,7 @@ pub fn run(mut app: Box<dyn App>) -> ! {
         .as_mut()
         .and_then(|storage| egui::app::get_value(storage.as_ref(), WINDOW_KEY));
     let event_loop = glutin::event_loop::EventLoop::with_user_event();
-    let display = create_display(app.name(), window_settings, &event_loop);
+    let display = create_display(app.name(), window_settings, app.is_resizable(), &event_loop);
 
     let repaint_signal = std::sync::Arc::new(GliumRepaintSignal(event_loop.create_proxy()));