diff --git a/lua/custom/init.lua b/lua/custom/init.lua
index 2fa90f5..dfb2252 100644
--- a/lua/custom/init.lua
+++ b/lua/custom/init.lua
@@ -4,7 +4,6 @@ g.maplocalleader = ";"
 
 opt.mouse = "" -- hardcore vim mode, disable the mouse
 opt.signcolumn = "yes"
-opt.spelllang = "en,de"
 opt.clipboard = "" -- don't just use the system clipboard
 opt.wrap = false
 opt.breakindent = false
@@ -106,6 +105,13 @@ opt.pumheight = 10 -- Maximum number of items to show in the popup menu
 opt.pumwidth = 10 -- Minimum width for the popup menu
 opt.pumblend = 10 -- Popup blend
 
+-- Spelling correction
+-- ===
+
+opt.spell = false -- manually enable spell with `set spell` or `<leader>ts`
+opt.spelllang = "en,de_de,"
+opt.spellsuggest = "double,50,timeout:5000"
+
 -- autocommands
 -- ===
 local function augroup(name)
diff --git a/spell/en.utf-8.add b/spell/en.utf-8.add
index 9b05773..5951639 100644
--- a/spell/en.utf-8.add
+++ b/spell/en.utf-8.add
@@ -271,3 +271,4 @@ PRs
 yaml
 netpong
 gehostet
+IoT
diff --git a/spell/en.utf-8.add.spl b/spell/en.utf-8.add.spl
index 6a6db88..e5192e0 100644
Binary files a/spell/en.utf-8.add.spl and b/spell/en.utf-8.add.spl differ