diff --git a/autoload/youcompleteme.vim b/autoload/youcompleteme.vim
index a0375485..0349cfb5 100644
--- a/autoload/youcompleteme.vim
+++ b/autoload/youcompleteme.vim
@@ -113,13 +113,13 @@ function! s:SetUpKeyMappings()
           \ ' pumvisible() ? "\<C-p>" : "\' . key .'"'
   endfor
 
-  if strlen(g:ycm_key_invoke_completion)
+  if !empty( g:ycm_key_invoke_completion )
     " <c-x><c-o> trigger omni completion, <c-p> deselects the first completion
     " candidate that vim selects by default
     exe 'inoremap <unique> ' . g:ycm_key_invoke_completion . ' <C-X><C-O><C-P>'
   endif
 
-  if strlen(g:ycm_key_detailed_diagnostics)
+  if !empty( g:ycm_key_detailed_diagnostics )
     exe 'nnoremap <unique> ' . g:ycm_key_detailed_diagnostics .
           \ ' :YcmShowDetailedDiagnostic<cr>'
   endif