diff --git a/plugin/signify.vim b/plugin/signify.vim
index f735caa..71b0d33 100644
--- a/plugin/signify.vim
+++ b/plugin/signify.vim
@@ -266,7 +266,7 @@ function! s:diff_get(path) abort
 
     if executable('cvs')
         let diff = system('cvs diff -U0 '. a:path .' 2>&1 | grep "^@@ "')
-        if !empty(diff)
+        if !v:shell_error
             return diff
         endif
     endif