diff --git a/runtime/ftplugin/haredoc.vim b/runtime/ftplugin/haredoc.vim
new file mode 100644
index 0000000..69030b4
--- /dev/null
+++ b/runtime/ftplugin/haredoc.vim
@@ -0,0 +1,44 @@
+" Vim filetype plugin.
+" Language:     Haredoc (Hare documentation format)
+" Maintainer:   Amelia Clarke <selene@perilune.dev>
+" Last Updated: 2024-05-02
+" Upstream:     https://git.sr.ht/~selene/hare.vim
+
+if exists('b:did_ftplugin')
+  finish
+endif
+let b:did_ftplugin = 1
+
+let s:cpo_save = &cpo
+set cpo&vim
+
+" Formatting settings.
+setlocal comments=:\	
+setlocal formatlistpat=^\ \\?-\ 
+setlocal formatoptions+=tnlj formatoptions-=c formatoptions-=q
+
+" Search for Hare modules.
+setlocal includeexpr=hare#FindModule(v:fname)
+setlocal isfname+=:
+setlocal suffixesadd=.ha
+
+" Add HAREPATH to the default search paths.
+setlocal path-=/usr/include,,
+let &l:path .= ',' .. hare#GetPath() .. ',,'
+
+let b:undo_ftplugin = 'setl com< flp< fo< inex< isf< pa< sua<'
+
+" Follow the Hare style guide by default.
+if get(g:, 'hare_recommended_style', 1)
+  setlocal noexpandtab
+  setlocal shiftwidth=0
+  setlocal softtabstop=0
+  setlocal tabstop=8
+  setlocal textwidth=80
+  let b:undo_ftplugin .= ' et< sts< sw< ts< tw<'
+endif
+
+let &cpo = s:cpo_save
+unlet s:cpo_save
+
+" vim: et sts=2 sw=2 ts=8