diff --git a/crates/egui/src/containers/popup.rs b/crates/egui/src/containers/popup.rs
index b63825e4..44dafc62 100644
--- a/crates/egui/src/containers/popup.rs
+++ b/crates/egui/src/containers/popup.rs
@@ -160,6 +160,7 @@ impl From<PopupKind> for UiKind {
     }
 }
 
+#[must_use = "Call `.show()` to actually display the popup"]
 pub struct Popup<'a> {
     id: Id,
     ctx: Context,