diff --git a/src/proto/vim9type.pro b/src/proto/vim9type.pro
index fb3cb8d..aaa1a71 100644
--- a/src/proto/vim9type.pro
+++ b/src/proto/vim9type.pro
@@ -27,7 +27,7 @@
 void set_type_on_stack(cctx_T *cctx, type_T *type, int offset);
 type_T *get_type_on_stack(cctx_T *cctx, int offset);
 type_T *get_decl_type_on_stack(cctx_T *cctx, int offset);
-type_T *get_member_type_from_stack(int count, int skip, type_T **decl_type, cctx_T *cctx);
+type_T *get_member_type_from_stack(int count, int skip, cctx_T *cctx);
 char *vartype_name(vartype_T type);
 char *type_name(type_T *type, char **tofree);
 void f_typename(typval_T *argvars, typval_T *rettv);
diff --git a/src/testdir/test_vim9_builtin.vim b/src/testdir/test_vim9_builtin.vim
index 557ddf2..ee32b39 100644
--- a/src/testdir/test_vim9_builtin.vim
+++ b/src/testdir/test_vim9_builtin.vim
@@ -2237,6 +2237,11 @@
       g:gl = l
       map(g:gl, (k, v) => true)
       assert_equal([true], g:gl)
+
+      assert_equal(['x'], [[1, 2]]->map((_, v) => 'x'))
+      assert_equal(['x'], [{a: 0}]->map((_, v) => 'x'))
+      assert_equal({a: 'x'}, {a: [1, 2]}->map((_, v) => 'x'))
+      assert_equal({a: 'x'}, {a: {b: 2}}->map((_, v) => 'x'))
   END
   v9.CheckDefAndScriptSuccess(lines)
 enddef
diff --git a/src/version.c b/src/version.c
index 37d653d..20bc28a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4310,
+/**/
     4309,
 /**/
     4308,
diff --git a/src/vim9instr.c b/src/vim9instr.c
index 60963a3..cf26650 100644
--- a/src/vim9instr.c
+++ b/src/vim9instr.c
@@ -1067,7 +1067,6 @@
 {
     isn_T	*isn;
     type_T	*member_type;
-    type_T	*decl_member_type;
     type_T	*type;
     type_T	*decl_type;
 
@@ -1078,10 +1077,9 @@
 
     // Get the member type and the declared member type from all the items on
     // the stack.
-    member_type = get_member_type_from_stack(count, 1,
-						      &decl_member_type, cctx);
+    member_type = get_member_type_from_stack(count, 1, cctx);
     type = get_list_type(member_type, cctx->ctx_type_list);
-    decl_type = get_list_type(decl_member_type, cctx->ctx_type_list);
+    decl_type = get_list_type(&t_any, cctx->ctx_type_list);
 
     // drop the value types
     cctx->ctx_type_stack.ga_len -= count;
@@ -1098,7 +1096,6 @@
 {
     isn_T	*isn;
     type_T	*member_type;
-    type_T	*decl_member_type;
     type_T	*type;
     type_T	*decl_type;
 
@@ -1107,10 +1104,9 @@
 	return FAIL;
     isn->isn_arg.number = count;
 
-    member_type = get_member_type_from_stack(count, 2,
-						      &decl_member_type, cctx);
+    member_type = get_member_type_from_stack(count, 2, cctx);
     type = get_dict_type(member_type, cctx->ctx_type_list);
-    decl_type = get_dict_type(decl_member_type, cctx->ctx_type_list);
+    decl_type = get_dict_type(&t_any, cctx->ctx_type_list);
 
     // drop the key and value types
     cctx->ctx_type_stack.ga_len -= 2 * count;
diff --git a/src/vim9type.c b/src/vim9type.c
index f72698c..62be6ac 100644
--- a/src/vim9type.c
+++ b/src/vim9type.c
@@ -1359,7 +1359,6 @@
 get_member_type_from_stack(
 	int	    count,
 	int	    skip,
-	type_T	    **decl_type,
 	cctx_T	    *cctx)
 {
     garray_T	*stack = &cctx->ctx_type_stack;
@@ -1367,32 +1366,24 @@
     garray_T    *type_gap = cctx->ctx_type_list;
     int		i;
     type_T	*result;
-    type_T	*decl_result;
     type_T	*type;
 
     // Use "unknown" for an empty list or dict.
     if (count == 0)
-    {
-	*decl_type = &t_unknown;
 	return &t_unknown;
-    }
 
     // Use the first value type for the list member type, then find the common
     // type from following items.
     typep = ((type2_T *)stack->ga_data) + stack->ga_len;
     result = (typep -(count * skip) + skip - 1)->type_curr;
-    decl_result = (typep -(count * skip) + skip - 1)->type_decl;
     for (i = 1; i < count; ++i)
     {
 	if (result == &t_any)
 	    break;  // won't get more common
 	type = (typep -((count - i) * skip) + skip - 1)->type_curr;
 	common_type(type, result, &result, type_gap);
-	type = (typep -((count - i) * skip) + skip - 1)->type_decl;
-	common_type(type, decl_result, &decl_result, type_gap);
     }
 
-    *decl_type = decl_result;
     return result;
 }