diff --git a/autoload/airline/extensions/undotree.vim b/autoload/airline/extensions/undotree.vim
index 1f1e3ac..3de1712 100644
--- a/autoload/airline/extensions/undotree.vim
+++ b/autoload/airline/extensions/undotree.vim
@@ -3,10 +3,12 @@
 
 function! airline#extensions#undotree#apply(...)
   if exists('t:undotree')
-    if &ft == 'undotree' && exists('*t:undotree.GetStatusLine')
-      call airline#extensions#apply_left_override('undo', '%{t:undotree.GetStatusLine()}')
-    else
-      call airline#extensions#apply_left_override('undotree', '%f')
+    if &ft == 'undotree'
+      if exists('*t:undotree.GetStatusLine')
+        call airline#extensions#apply_left_override('undo', '%{t:undotree.GetStatusLine()}')
+      else
+        call airline#extensions#apply_left_override('undotree', '%f')
+      endif
     endif
 
     if &ft == 'diff' && exists('*t:diffpanel.GetStatusLine')