diff --git a/crates/ui-egui/src/dialogs/insert_function.rs b/crates/ui-egui/src/dialogs/insert_function.rs
index 6a93530f7..38a695a80 100644
--- a/crates/ui-egui/src/dialogs/insert_function.rs
+++ b/crates/ui-egui/src/dialogs/insert_function.rs
@@ -29,7 +29,10 @@ pub(super) fn insert_function(app: &mut SheetApp, ui: &mut egui::Ui, d: &mut Dia
     } else {
         lib::category_id(&saved).map(lib::category_label).unwrap_or(MOST_RECENTLY_USED).to_string()
     };
-    ui.horizontal(|ui| {
+    // The category list is the dialog's only menu, so a menu open as the frame starts is its own
+    // (Enter on a row picks it and closes the menu in this frame).
+    let menu_was_open = egui::Popup::is_any_open(ui.ctx());
+    let picker = ui.horizontal(|ui| {
         let label = ui.label(language.tr("Or select a category:"));
         craft_ui::ComboBox::from_id_salt("insertFunctionCategory")
             .width(220.0)
@@ -40,8 +43,14 @@ pub(super) fn insert_function(app: &mut SheetApp, ui: &mut egui::Ui, d: &mut Dia
                 }
             })
             .response
-            .labelled_by(label.id);
+            .labelled_by(label.id)
     });
+    // Enter on the category list or in its menu opens it or picks a category, as Space does
+    // (egui clicks a focused control on either key); it does not also confirm the dialog.
+    let picker = picker.inner;
+    if menu_was_open || picker.has_focus() || craft_ui::ComboBox::is_open(ui.ctx(), picker.id) {
+        ui.input_mut(|i| i.consume_key(egui::Modifiers::NONE, egui::Key::Enter));
+    }
     if category != saved {
         d.list_index = 0;
     }
diff --git a/crates/ui-egui/tests/it/function_library.rs b/crates/ui-egui/tests/it/function_library.rs
index dd86f4652..a1a7a1a37 100644
--- a/crates/ui-egui/tests/it/function_library.rs
+++ b/crates/ui-egui/tests/it/function_library.rs
@@ -263,6 +263,41 @@ fn insert_function_lets_tab_reach_the_category_list() {
     assert_eq!(listed(&h), before + 1, "the list is open");
 }
 
+#[test]
+fn enter_on_the_category_list_does_not_confirm_insert_function() {
+    use egui::accesskit::Role;
+    let mut h = formulas_tab(1440.0);
+    click(&mut h, "Insert Function");
+    h.run_steps(3);
+    let open = |h: &Harness| h.state().dialog.as_ref().is_some_and(|d| d.name == "insertFunction");
+    let listed = |h: &Harness| h.get_all_by_label("Date & Time").count();
+    let closed = listed(&h);
+    h.input_mut().events.extend([key_event(Key::Tab, true), key_event(Key::Tab, false)]);
+    h.run_steps(5);
+    assert!(h.get_by_role(Role::ComboBox).is_focused(), "Tab reaches the category list");
+    // Enter on the focused list opens it, as Space does; the dialog stays open and nothing is
+    // inserted.
+    h.input_mut().events.extend([key_event(Key::Enter, true), key_event(Key::Enter, false)]);
+    h.run_steps(3);
+    assert!(open(&h), "Enter on the category list leaves the dialog open");
+    assert_eq!(editor_text(&h), None, "no function is inserted");
+    assert_eq!(listed(&h), closed + 1, "Enter opens the list");
+    // Enter again, with the list open, closes it and still does not confirm.
+    h.input_mut().events.extend([key_event(Key::Enter, true), key_event(Key::Enter, false)]);
+    h.run_steps(3);
+    assert!(open(&h), "Enter in the open list leaves the dialog open");
+    assert_eq!(editor_text(&h), None);
+    // Back in the search box (Shift+Tab), Enter confirms as before.
+    let shift_tab = |pressed| Event::Key { key: Key::Tab, physical_key: None, pressed, repeat: false, modifiers: Modifiers::SHIFT };
+    h.input_mut().events.extend([shift_tab(true), shift_tab(false)]);
+    h.run_steps(3);
+    assert!(!h.get_by_role(Role::ComboBox).is_focused(), "Shift+Tab leaves the category list");
+    h.input_mut().events.extend([key_event(Key::Enter, true), key_event(Key::Enter, false)]);
+    h.run_steps(3);
+    assert!(!open(&h), "Enter in the search box confirms");
+    assert!(editor_text(&h).is_some_and(|t| t.starts_with('=') && t.ends_with('(')), "{:?}", editor_text(&h));
+}
+
 /// The text shapes the last frame painted, with their left edge and width.
 fn painted_text(h: &Harness) -> Vec<(String, f32, f32)> {
     let mut out = Vec::new();