diff --git a/autoload/sy/util.vim b/autoload/sy/util.vim
index 0501e8d..9f100d8 100644
--- a/autoload/sy/util.vim
+++ b/autoload/sy/util.vim
@@ -30,7 +30,9 @@ function! sy#util#refresh_windows() abort
     let winnr = winnr()
   endif
 
-  windo if exists('b:sy') | call sy#start() | endif
+  if !get(g:, 'signify_cmdwin_active')
+    windo if exists('b:sy') | call sy#start() | endif
+  endif
 
   if exists('winid')
     call win_gotoid(winid)
diff --git a/doc/signify.txt b/doc/signify.txt
index 955fea9..8256958 100644
--- a/doc/signify.txt
+++ b/doc/signify.txt
@@ -291,9 +291,12 @@ NOTE: This also saves the buffer to disk!
                                                *g:signify_update_on_focusgained*  >
     let g:signify_update_on_focusgained = 0
 <
-Update signs when the window holding Vim gains focus.
+Update the signs on |FocusGained|, thus when the window holding Vim gains focus.
+It does so by executing |signify-:SignifyRefresh|.
 
-NOTE: This works for all GUIs and even a few terminal emulators.
+NOTE: The |FocusGained| event is fired for all GUIs and even a few terminal
+emulators. If you use tmux, put `set-option -g focus-events on` in your
+tmux.conf.
 
 ------------------------------------------------------------------------------
                                                       *g:signify_line_highlight*  >
@@ -421,6 +424,8 @@ Toggle line highlighting for lines containing changes.
 <
 Refresh signs in all windows.
 
+NOTE: Nothing will happen, if :SignifyRefresh is used from the |cmdline-window|.
+
 ------------------------------------------------------------------------------
                                                           *signify-:SignifyFold*  >
     :SignifyFold[!]
diff --git a/plugin/signify.vim b/plugin/signify.vim
index 51a4120..f3cc5da 100644
--- a/plugin/signify.vim
+++ b/plugin/signify.vim
@@ -18,6 +18,9 @@ augroup signify
   autocmd QuickFixCmdPre  *vimgrep* let g:signify_locked = 1
   autocmd QuickFixCmdPost *vimgrep* let g:signify_locked = 0
 
+  autocmd CmdwinEnter * let g:signify_cmdwin_active = 1
+  autocmd CmdwinLeave * let g:signify_cmdwin_active = 0
+
   autocmd BufWritePost * call sy#start()
 
   if get(g:, 'signify_realtime') && has('patch-7.4.1967')