diff --git a/src/testdir/test_filter_map.vim b/src/testdir/test_filter_map.vim
index 72a8d84..e144538 100644
--- a/src/testdir/test_filter_map.vim
+++ b/src/testdir/test_filter_map.vim
@@ -57,6 +57,9 @@
   let x = {"x":10}
   let r = map(range(2), 'filter(copy(x), "1")')
   call assert_equal([x, x], r)
+
+  let r = map(copy(x), 'filter(copy(x), "1")')
+  call assert_equal({"x": x}, r)
 endfunc
 
 " dict with funcref
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 6984c23..20718bc 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -1543,6 +1543,10 @@
   let files = readdir('Xdir', {x -> len(add(l, x)) == 2 ? -1 : 1})
   call assert_equal(1, len(files))
 
+  " Nested readdir() must not crash
+  let files = readdir('Xdir', 'readdir("Xdir", "1") != []')
+  call sort(files)->assert_equal(['bar.txt', 'dir', 'foo.txt'])
+
   eval 'Xdir'->delete('rf')
 endfunc