diff --git a/.gitmodules b/.gitmodules
index b31f245..b001735 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -43,3 +43,6 @@
 [submodule "qutebrowser/.config/qutebrowser/catppuccin"]
 	path = qutebrowser/.config/qutebrowser/catppuccin
 	url = https://github.com/catppuccin/qutebrowser.git
+[submodule "vim/.vim/pack/default/start/undotree"]
+	path = vim/.vim/pack/default/start/undotree
+	url = https://github.com/mbbill/undotree.git
diff --git a/vim/.vim/pack/default/start/undotree b/vim/.vim/pack/default/start/undotree
new file mode 160000
index 0000000..36ff7ab
--- /dev/null
+++ b/vim/.vim/pack/default/start/undotree
@@ -0,0 +1 @@
+Subproject commit 36ff7abb6b60980338344982ad4cdf03f7961ecd
diff --git a/vim/.vimrc b/vim/.vimrc
index 309818c..6f825f7 100644
--- a/vim/.vimrc
+++ b/vim/.vimrc
@@ -259,7 +259,7 @@ let g:mucomplete#completion_delay = 0
 "autocmd InsertCharPre * call OpenCompletion()
 "
 set completeopt+=longest,menu,menuone,preview,noselect,noinsert
-set splitkeep=screen
+" set splitkeep=screen
 "" set completeopt+=menuone,noselect,noinsert
 ""
 " autocmd InsertLeave,CompleteDone * if pumvisible() == 0 | pclose | endif
@@ -278,6 +278,14 @@ set splitkeep=screen
 "    endif
 " endfunction
 
+""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
+"
+" undotree
+"
+""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
+
+nnoremap <F5> :UndotreeToggle<CR>
+
 """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 "
 " Remove conceal from Markdown when Insert mode is set