diff --git a/coc-settings.json b/coc-settings.json
new file mode 100644
index 0000000..4942f3d
--- /dev/null
+++ b/coc-settings.json
@@ -0,0 +1,15 @@
+{
+    "languageserver": {
+        "rust": {
+            "command": "rustup",
+            "args": ["run", "nightly", "rust-analyzer"],
+            "filetypes": ["rust"],
+            "rootPatterns": ["Cargo.toml"]
+        },
+        "elm": {
+            "command": "elm-language-server",
+            "filetypes": ["elm"],
+            "rootPatterns": ["elm.json"]
+        }
+    }
+}
diff --git a/init.vim b/init.vim
index 1382722..0fdb498 100644
--- a/init.vim
+++ b/init.vim
@@ -3,35 +3,24 @@ set nocompatible
 
 " PLUGNIS ###########################################################{{{
 call plug#begin()
-if has('nvim')
-  Plug 'Shougo/deoplete.nvim', { 'do': ':UpdateRemotePlugins' }
-else
-  Plug 'Shougo/deoplete.nvim'
-  Plug 'roxma/nvim-yarp'
-  Plug 'roxma/vim-hug-neovim-rpc'
-endif
+
+" Conquer of Completion
+Plug 'neoclide/coc.nvim', {'branch': 'release'}
 
 " General plugins
 Plug 'vim-airline/vim-airline'
 Plug 'vim-airline/vim-airline-themes'
 Plug 'https://gitea.tforgione.fr/tforgione/peach.git'
 Plug 'scrooloose/nerdtree'
-Plug 'w0rp/ale'
 Plug 'tpope/vim-abolish'
 
 " Language specific plugins
 
-" C++
-Plug 'Shougo/deoplete-clangx'
-
 " Rust
 Plug 'rust-lang/rust.vim'
-Plug 'racer-rust/vim-racer'
-Plug 'sebastianmarkow/deoplete-rust'
 
 " Elm
 Plug 'ElmCast/elm-vim'
-Plug 'antew/vim-elm-language-server'
 
 " Toml
 Plug 'cespare/vim-toml'
@@ -157,11 +146,46 @@ let g:markdown_composer_browser = 'firefox'
 let g:instant_markdown_autostart = 0
 " }}}
 
-" CODE COMPLETION ###################################################{{{
+" COC CONFIG ########################################################{{{
 
-" Use deoplete
-let g:deoplete#enable_at_startup = 1
-autocmd FileType elm call deoplete#custom#buffer_option('auto_complete', v:false)
+" Use `[g` and `]g` to navigate diagnostics
+" Use `:CocDiagnostics` to get all diagnostics of current buffer in location list.
+nmap <silent> gp <Plug>(coc-diagnostic-prev)
+nmap <silent> gn <Plug>(coc-diagnostic-next)
+
+" GoTo code navigation.
+nmap <silent> gd <Plug>(coc-definition)
+nmap <silent> gy <Plug>(coc-type-definition)
+nmap <silent> gi <Plug>(coc-implementation)
+nmap <silent> gr <Plug>(coc-references)
+
+" Use K to show documentation in preview window.
+nnoremap <silent> K :call <SID>show_documentation()<CR>
+
+
+function! s:show_documentation()
+  if (index(['vim','help'], &filetype) >= 0)
+    execute 'h '.expand('<cword>')
+  elseif (coc#rpc#ready())
+    call CocActionAsync('doHover')
+  else
+    execute '!' . &keywordprg . " " . expand('<cword>')
+  endif
+endfunction
+
+" Having longer updatetime (default is 4000 ms = 4 s) leads to noticeable
+" delays and poor user experience.
+set updatetime=300
+
+" Highlight the symbol and its references when holding the cursor.
+autocmd CursorHold * silent call CocActionAsync('highlight')
+
+" Symbol renaming.
+nmap <leader>rn <Plug>(coc-rename)
+
+" Formatting selected code.
+xmap <leader>f  <Plug>(coc-format-selected)
+nmap <leader>f  <Plug>(coc-format-selected)
 
 " Autoclose preview
 autocmd CursorMovedI * if pumvisible() == 0|pclose|endif
@@ -169,19 +193,7 @@ autocmd InsertLeave * if pumvisible() == 0|pclose|endif
 
 " Complete on tab
 inoremap <expr><TAB>  pumvisible() ? "\<C-n>" : "\<TAB>"
-
 " }}}
 
 " CUSTOM THINGS DEPENDING ON ENV ####################################{{{
 let g:rustfmt_autosave = 1
-let g:ale_linters = {}
-let g:ale_c_parse_compile_commands=1
-let g:ale_elm_ls_use_global = 1
-let g:ale_linters_ignore = { 'elm': ['make'] }
-let g:ale_lint_on_text_changed = 0
-if $NVIM_DISABLE_PYTHON_LINTER == '1'
-    let g:ale_linters.python = []
-endif
-if $NVIM_DISABLE_JAVA_LINTER == '1'
-    let g:ale_linters.java = []
-endif