diff --git a/src/widgets/sign_widget.h b/src/widgets/sign_widget.h
--- a/src/widgets/sign_widget.h
+++ b/src/widgets/sign_widget.h
@@ -21,6 +21,7 @@ enum SignListWidgets {
 	WID_SIL_FILTER_TEXT,           ///< Text box for typing a filter string.
 	WID_SIL_FILTER_MATCH_CASE_BTN, ///< Button to toggle if case sensitive filtering should be used.
 	WID_SIL_FILTER_CLEAR_BTN,      ///< Button to clear the filter.
+	WID_SIL_FILTER_ENTER_BTN,      ///< Scroll to first sign.
 };
 
 /** Widgets of the #SignWindow class. */