diff --git a/src/evalwindow.c b/src/evalwindow.c
index 53fd1e3..43a6d63 100644
--- a/src/evalwindow.c
+++ b/src/evalwindow.c
@@ -395,6 +395,9 @@
     if (dict == NULL)
 	return NULL;
 
+    // make sure w_botline is valid
+    validate_botline_win(wp);
+
     dict_add_number(dict, "tabnr", tpnr);
     dict_add_number(dict, "winnr", winnr);
     dict_add_number(dict, "winid", wp->w_id);