diff --git a/Userland/Applications/FontEditor/MainWidget.cpp b/Userland/Applications/FontEditor/MainWidget.cpp
index ef32b47f4e..ef70c30878 100644
--- a/Userland/Applications/FontEditor/MainWidget.cpp
+++ b/Userland/Applications/FontEditor/MainWidget.cpp
@@ -73,7 +73,7 @@ ErrorOr<RefPtr<GUI::Window>> MainWidget::create_preview_window()
 
     m_preview_textbox = find_descendant_of_type_named<GUI::TextBox>("preview_textbox");
     m_preview_textbox->on_change = [&] {
-        auto preview = DeprecatedString::formatted("{}\n{}", m_preview_textbox->text(), Unicode::to_unicode_uppercase_full(m_preview_textbox->text()));
+        auto preview = DeprecatedString::formatted("{}\n{}", m_preview_textbox->text(), Unicode::to_unicode_uppercase_full(m_preview_textbox->text()).release_value_but_fixme_should_propagate_errors());
         m_preview_label->set_text(preview);
     };
     m_preview_textbox->set_text(pangrams[0]);