diff --git a/src/input.c b/src/input.c
index 343213b720..65621f24c1 100644
--- a/src/input.c
+++ b/src/input.c
@@ -1250,8 +1250,9 @@ static void input_update_tooltip(rct_window *w, int widgetIndex, int x, int y)
 		}
 	}
 	else {
-		if (RCT2_GLOBAL(RCT2_ADDRESS_TOOLTIP_WINDOW_CLASS, rct_windowclass) != w->classification ||
-			RCT2_GLOBAL(RCT2_ADDRESS_TOOLTIP_WINDOW_NUMBER, rct_windownumber) != w->number ||
+		if (((w != NULL) &&
+			(RCT2_GLOBAL(RCT2_ADDRESS_TOOLTIP_WINDOW_CLASS, rct_windowclass) != w->classification ||
+			RCT2_GLOBAL(RCT2_ADDRESS_TOOLTIP_WINDOW_NUMBER, rct_windownumber) != w->number)) ||
 			RCT2_GLOBAL(RCT2_ADDRESS_TOOLTIP_WIDGET_INDEX, uint16) != widgetIndex
 			) {
 			window_tooltip_close();