diff --git a/runtime/autoload/dist/ft.vim b/runtime/autoload/dist/ft.vim
index a3db4ae..366d7b0 100644
--- a/runtime/autoload/dist/ft.vim
+++ b/runtime/autoload/dist/ft.vim
@@ -811,6 +811,23 @@
   endwhile
 endfunc
 
+" This function is called for all files under */debian/patches/*, make sure not
+" to non-dep3patch files, such as README and other text files.
+func dist#ft#Dep3patch()
+  if expand('%:t') ==# 'series'
+    return
+  endif
+
+  for ln in getline(1, 100)
+    if ln =~# '^\%(Description\|Subject\|Origin\|Bug\|Forwarded\|Author\|From\|Reviewed-by\|Acked-by\|Last-Updated\|Applied-Upstream\):'
+      setf dep3patch
+      return
+    elseif ln =~# '^---'
+      " end of headers found. stop processing
+      return
+    endif
+  endfor
+endfunc
 
 " Restore 'cpoptions'
 let &cpo = s:cpo_save
diff --git a/runtime/filetype.vim b/runtime/filetype.vim
index d99527f..7740d8f 100644
--- a/runtime/filetype.vim
+++ b/runtime/filetype.vim
@@ -490,6 +490,9 @@
 " Dictd config
 au BufNewFile,BufRead dictd*.conf		setf dictdconf
 
+" DEP3 formatted patch files
+au BufNewFile,BufRead */debian/patches/*	call dist#ft#Dep3patch()
+
 " Diff files
 au BufNewFile,BufRead *.diff,*.rej		setf diff
 au BufNewFile,BufRead *.patch