diff --git a/doc/syntastic.txt b/doc/syntastic.txt
index 7f8cc325..52e5b887 100644
--- a/doc/syntastic.txt
+++ b/doc/syntastic.txt
@@ -40,6 +40,7 @@ CONTENTS                                                  *syntastic-contents*
         6.3.Interaction with the fish shell........|syntastic-fish|
         6.4.Using syntastic with the fizsh shell...|syntastic-fizsh|
         6.5.Interaction with Eclim.................|syntastic-eclim|
+        6.6.Interaction with vim-virtualenv........|syntastic-vim-virtualenv|
     7.About........................................|syntastic-about|
     8.License......................................|syntastic-license|
 
@@ -673,6 +674,14 @@ this writing there are several reports that 'Eclim' triggers a bug in Vim that
 makes syntastic forget some of its configuration parameters. No solutions or
 workarounds are known for now.
 
+------------------------------------------------------------------------------
+6.6. Interaction with vim-virtualenv                *syntastic-vim-virtualenv*
+
+At the time of this writing, syntastic can't run checkers installed
+in Python virtual environments activated by 'vim-virtualenv' (see
+https://github.com/jmcantrell/vim-virtualenv).  This is a limitation of
+'vim-virtualenv'.
+
 ==============================================================================
 7. About                                                     *syntastic-about*
 
diff --git a/plugin/syntastic.vim b/plugin/syntastic.vim
index cfcbb370..041a2bd1 100644
--- a/plugin/syntastic.vim
+++ b/plugin/syntastic.vim
@@ -18,7 +18,7 @@ if has('reltime')
     let g:syntastic_start = reltime()
 endif
 
-let g:syntastic_version = '3.4.0-13'
+let g:syntastic_version = '3.4.0-21'
 
 " Sanity checks {{{1