diff --git a/src/testdir/test_cd.vim b/src/testdir/test_cd.vim
new file mode 100644
index 0000000..e573419
--- /dev/null
+++ b/src/testdir/test_cd.vim
@@ -0,0 +1,13 @@
+" Test for :cd
+
+func Test_cd_large_path()
+  " This used to crash with a heap write overflow.
+  call assert_fails('cd ' . repeat('x', 5000), 'E472:')
+endfunc
+
+func Test_cd_up_and_down()
+  let path = getcwd()
+  cd ..
+  exe 'cd ' . path
+  call assert_equal(path, getcwd())
+endfunc