diff --git a/.config/nvim/lazy-lock.json b/.config/nvim/lazy-lock.json
index 209abc2..d4685e4 100644
--- a/.config/nvim/lazy-lock.json
+++ b/.config/nvim/lazy-lock.json
@@ -51,6 +51,7 @@
   "tidy.nvim": { "branch": "triggerable-tidy", "commit": "1cbed7676273057c8af22438deaae73cd5cb96b5" },
   "todo-comments.nvim": { "branch": "main", "commit": "4a6737a8d70fe1ac55c64dfa47fcb189ca431872" },
   "trouble.nvim": { "branch": "main", "commit": "f1168feada93c0154ede4d1fe9183bf69bac54ea" },
+  "undotree": { "branch": "master", "commit": "a1758ba9990b7189f601a3a5acdfc8ca3907a700" },
   "vim-hug-neovim-rpc": { "branch": "master", "commit": "93ae38792bc197c3bdffa2716ae493c67a5e7957" },
   "vim-illuminate": { "branch": "master", "commit": "3bd2ab64b5d63b29e05691e624927e5ebbf0fb86" },
   "vim-markdown": { "branch": "master", "commit": "46add6c3017d3e4035dc10ffa9cb54221d8dfe1a" },
diff --git a/.config/nvim/lua/keymap.lua b/.config/nvim/lua/keymap.lua
index c9ddf8a..ea9be7c 100644
--- a/.config/nvim/lua/keymap.lua
+++ b/.config/nvim/lua/keymap.lua
@@ -23,8 +23,6 @@ m.nname("<leader>t", "Terminal")
 m.nnoremap("Zt",  '<NOP>')
 m.nnoremap("ZT",  '<NOP>')
 m.nnoremap("<Space>",  '<NOP>')
-m.inoremap("<F1>",  '<NOP>')
-m.nnoremap("<F1>",  '<NOP>')
 m.inoremap("<F2>",  '<NOP>')
 m.inoremap("<F3>",  '<NOP>')
 m.inoremap("<F4>",  '<NOP>')
@@ -66,6 +64,9 @@ m.nmap('<F3>', ':AerialToggle!<CR>', 'CTags: toggle')
 -- nvim-tree/nvim-tree.lua
 m.nmap("<F2>", ':NvimTreeToggle toggle<CR>', 'File tree: toggle')
 
+-- mbbill/undotree
+m.nmap("<F1>", ':UndotreeToggle<CR>', 'Undo tree: toggle')
+
 -- numtostr/fterm.nvim
 m.nnoremap("<leader>tt", require("FTerm").toggle, 'Terminal: open')
 m.tnoremap("<leader>tt", require("FTerm").toggle, 'Terminal: open')
diff --git a/.config/nvim/lua/plugins/undotree.lua b/.config/nvim/lua/plugins/undotree.lua
new file mode 100644
index 0000000..d35bee7
--- /dev/null
+++ b/.config/nvim/lua/plugins/undotree.lua
@@ -0,0 +1,6 @@
+return {
+  -- tree style undo visualizer
+  {
+    'mbbill/undotree'
+  }
+}