diff --git a/after/plugin/lsp.lua b/after/plugin/lsp.lua
index 6fd22cf..06ea967 100644
--- a/after/plugin/lsp.lua
+++ b/after/plugin/lsp.lua
@@ -11,6 +11,12 @@ lsp.ensure_installed({
   'tsserver',
   'texlab',
   'pyright',
+  'sumneko_lua'
 })
 
+lsp.on_attach(function(client, bufnr)
+  local opts = {buffer = bufnr, remap=false}
+  vim.keymap.set("n", "gd", function() vim.lsp.buf.definition() end, opts)
+end)
+
 lsp.setup()
diff --git a/after/plugin/nvimtree.lua b/after/plugin/nvimtree.lua
new file mode 100644
index 0000000..919f566
--- /dev/null
+++ b/after/plugin/nvimtree.lua
@@ -0,0 +1,6 @@
+
+-- empty setup using defaults
+nvimtree = require("nvim-tree")
+
+vim.keymap.set("n", "<C-n>", nvimtree.toggle)
+nvimtree.setup()
diff --git a/lua/junikim/packer.lua b/lua/junikim/packer.lua
index 7ca7a4c..1f7a8bd 100644
--- a/lua/junikim/packer.lua
+++ b/lua/junikim/packer.lua
@@ -45,4 +45,11 @@ return require('packer').startup(function(use)
 
   use 'mattn/emmet-vim'
   use 'lervag/vimtex'
+  use {
+    'nvim-tree/nvim-tree.lua',
+    requires = {
+      'nvim-tree/nvim-web-devicons', -- optional, for file icons
+    },
+    tag = 'nightly' -- optional, updated every week. (see issue #1193)
+  }
 end)
diff --git a/plugin/packer_compiled.lua b/plugin/packer_compiled.lua
index 1eecb98..fadc105 100644
--- a/plugin/packer_compiled.lua
+++ b/plugin/packer_compiled.lua
@@ -145,6 +145,11 @@ _G.packer_plugins = {
     path = "/home/junikim/.local/share/nvim/site/pack/packer/start/nvim-lspconfig",
     url = "https://github.com/neovim/nvim-lspconfig"
   },
+  ["nvim-tree.lua"] = {
+    loaded = true,
+    path = "/home/junikim/.local/share/nvim/site/pack/packer/start/nvim-tree.lua",
+    url = "https://github.com/nvim-tree/nvim-tree.lua"
+  },
   ["nvim-treesitter"] = {
     loaded = true,
     path = "/home/junikim/.local/share/nvim/site/pack/packer/start/nvim-treesitter",