diff --git a/after/syntax/c.vim b/after/syntax/c.vim
index eac2c81..2e1be1c 100644
--- a/after/syntax/c.vim
+++ b/after/syntax/c.vim
@@ -23,8 +23,8 @@ syn match cFunction '\w[A-Za-z0-9_]*\ze\s*('
 syn match cLabel '^\s*\w[A-Za-z0-9_]\+\ze::\@!' contains=cppAccess
 
 " Match Doxygen comments
-let g:c_enable_doxygen_highlights = get(g:, 'c_enable_doxygen_highlights', 1)
-if g:c_enable_doxygen_highlights
+let g:c_doxygen = get(g:, 'c_doxygen', 1)
+if exists('g:c_doxygen') && g:c_doxygen
   syn region cDoxygen oneline matchgroup=cComment start='\/\/\/\s*@brief\s\+' end='$'
   syn region cDoxygen oneline matchgroup=cComment start='\/\/\/\s*@tparam\s\+' end='\(\s.*$\|$\)'
   syn region cDoxygen oneline matchgroup=cComment start='\/\/\/\s*@param\(\[\(\|in\|out\|inout\)\]\)\=\s\+' end='\(\s.*$\|$\)'