diff --git a/src/list.c b/src/list.c
index 86c1679..3a6ea97 100644
--- a/src/list.c
+++ b/src/list.c
@@ -1216,7 +1216,11 @@
     copy = list_alloc();
     if (copy != NULL)
     {
-	copy->lv_type = alloc_type(top || deep ? &t_list_any: orig->lv_type);
+	if (orig->lv_type == NULL)
+	    copy->lv_type = NULL;
+	else
+	    copy->lv_type = alloc_type(top || deep
+						 ? &t_list_any: orig->lv_type);
 	if (copyID != 0)
 	{
 	    // Do this before adding the items, because one of the items may
diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index c6466d3..a4e3e9e 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -1495,6 +1495,9 @@
 
       # result of glob() is "any", runtime type check
       var sl: list<string> = glob('*.txt', false, true) + ['']
+
+      var lln: list<list<number>> = [[1] + [2]]
+      assert_equal([[1, 2]], lln)
   END
   v9.CheckDefAndScriptSuccess(lines)
 enddef
diff --git a/src/version.c b/src/version.c
index 0419978..5140eb9 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4293,
+/**/
     4292,
 /**/
     4291,