diff --git a/src/window.rs b/src/window.rs
index 96189872f8..27184d4c76 100644
--- a/src/window.rs
+++ b/src/window.rs
@@ -85,6 +85,7 @@ impl WindowId {
 
 /// Object that allows building windows.
 #[derive(Clone, Default)]
+#[must_use]
 pub struct WindowBuilder {
     /// The attributes to use to create the window.
     pub window: WindowAttributes,