diff --git a/autoload/utils.vim b/autoload/utils.vim
index 73c003b..6afda90 100644
--- a/autoload/utils.vim
+++ b/autoload/utils.vim
@@ -31,13 +31,13 @@ endfunction
 " Check if a colorscheme exists in runtimepath.
 " The following two functions are inspired by https://stackoverflow.com/a/5703164/6064933.
 function! utils#HasColorscheme(name) abort
-  let l:pat = 'colors/' . a:name . '.vim'
+  let l:pat = printf('colors/%s.vim', a:name)
   return !empty(globpath(&runtimepath, l:pat))
 endfunction
 
 " Check if an Airline theme exists in runtimepath.
 function! utils#HasAirlinetheme(name) abort
-  let l:pat = 'autoload/airline/themes/' . a:name . '.vim'
+  let l:pat = printf('autoload/airline/themes/%s.vim', a:name)
   return !empty(globpath(&runtimepath, l:pat))
 endfunction
 
@@ -72,7 +72,7 @@ function! utils#MyFoldText() abort
   let folded_line_num = v:foldend - v:foldstart
   let line_text = substitute(line, '^"{\+', '', 'g')
   let fillcharcount = &textwidth - len(line_text) - len(folded_line_num) - 10
-  return '+'. repeat('-', 4) . line_text . repeat('.', fillcharcount) . ' (' . folded_line_num . ' L)'
+  return printf('+%s%s%s (%s L)', repeat('-', 4), line_text, repeat('.', fillcharcount), folded_line_num)
 endfunction
 
 " Toggle cursor column
diff --git a/init.vim b/init.vim
index a32dd4c..69c6eaf 100644
--- a/init.vim
+++ b/init.vim
@@ -65,7 +65,7 @@ let g:config_file_list = ['variables.vim',
   \ ]
 
 for s:fname in g:config_file_list
-  execute 'source ' . g:nvim_config_root . '/' . s:fname
+  execute printf('source %s/%s', g:nvim_config_root, s:fname)
 endfor
 "}
 
diff --git a/mappings.vim b/mappings.vim
index b3f8cab..5c4a0a1 100644
--- a/mappings.vim
+++ b/mappings.vim
@@ -49,8 +49,8 @@ nnoremap <silent> \d :bprevious <bar> bdelete #<CR>
 
 " Insert a blank line below or above current line (do not move the cursor),
 " see https://stackoverflow.com/a/16136133/6064933
-nnoremap <expr> oo 'm`' . v:count1 . 'o<Esc>``'
-nnoremap <expr> OO 'm`' . v:count1 . 'O<Esc>``'
+nnoremap <expr> oo printf('m`%so<ESC>``', v:count1)
+nnoremap <expr> OO printf('m`%sO<ESC>``', v:count1)
 
 " nnoremap oo @='m`o<c-v><Esc>``'<cr>
 " nnoremap OO @='m`O<c-v><Esc>``'<cr>
diff --git a/plugins.vim b/plugins.vim
index ada53ea..4fe0376 100644
--- a/plugins.vim
+++ b/plugins.vim
@@ -13,8 +13,8 @@ if g:is_win || g:is_mac
   if empty(glob(g:VIM_PLUG_PATH))
     if executable('curl')
       echomsg 'Installing Vim-plug on your system'
-      silent execute '!curl -fLo ' . g:VIM_PLUG_PATH . ' --create-dirs '
-            \ . 'https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim'
+      let l:vim_plug_furl = 'https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim'
+      silent execute printf('!curl -fLo %s --create-dirs %s', l:vim_plug_furl, g:VIM_PLUG_PATH)
       augroup plug_init
           autocmd!
           autocmd VimEnter * PlugInstall --sync | quit |source $MYVIMRC