diff --git a/runtime/indent/xml.vim b/runtime/indent/xml.vim
index da65417..5bf53ad 100644
--- a/runtime/indent/xml.vim
+++ b/runtime/indent/xml.vim
@@ -39,6 +39,8 @@
 " autoindent: used when the indentexpr returns -1
 setlocal autoindent
 
+let b:undo_indent = "setl ai< inde< indk<"
+
 if !exists('b:xml_indent_open')
     let b:xml_indent_open = '.\{-}<[:A-Z_a-z]'
     " pre tag, e.g. <address>
@@ -51,6 +53,10 @@
     " let b:xml_indent_close = '.\{-}</\(address\)\@!'
 endif
 
+if !exists('b:xml_indent_continuation_filetype')
+    let b:xml_indent_continuation_filetype = 'xml'
+endif
+
 let &cpo = s:keepcpo
 unlet s:keepcpo
 
@@ -162,7 +168,7 @@
 
 func! <SID>IsXMLContinuation(line)
     " Checks, whether or not the line matches a start-of-tag
-    return a:line !~ '^\s*<' && &ft is# 'xml'
+    return a:line !~ '^\s*<' && &ft =~# b:xml_indent_continuation_filetype
 endfunc
 
 func! <SID>HasNoTagEnd(line)