diff --git a/autoload/ale/c.vim b/autoload/ale/c.vim
index e7b43d88..ce59ae31 100644
--- a/autoload/ale/c.vim
+++ b/autoload/ale/c.vim
@@ -55,7 +55,7 @@ function! ale#c#ParseCFlags(path_prefix, cflag_line) abort
         " Check if cflag contained a '-' and should not have been splitted
         let l:option_list = split(l:option, '\zs')
 
-        if l:option_list[-1] isnot# ' '
+        if len(l:option_list) > 0 && l:option_list[-1] isnot# ' '
             continue
         endif
 
diff --git a/test/test_c_flag_parsing.vader b/test/test_c_flag_parsing.vader
index a4e00452..f7bfaa04 100644
--- a/test/test_c_flag_parsing.vader
+++ b/test/test_c_flag_parsing.vader
@@ -74,7 +74,7 @@ Execute(ParseCFlags should ignore -T and other arguments):
   \   . ' -DTEST=`date +%s`',
   \ ale#c#ParseCFlags(
   \   ale#path#Simplify(g:dir. '/test_c_projects/makefile_project'),
-  \   'gcc -Dgoal=9 -Tlinkerfile.ld blabla -Isubdir '
+  \   'gcc -Dgoal=9 -Tlinkerfile.ld blabla -Isubdir --sysroot=subdir '
   \     .  '-I'. ale#path#Simplify('kernel/include')
   \     .  ' -DTEST=`date +%s` -c file.c'
   \ )