diff --git a/IkiWiki/Render.pm b/IkiWiki/Render.pm
index ab3ccd7ae..90058199c 100644
--- a/IkiWiki/Render.pm
+++ b/IkiWiki/Render.pm
@@ -319,6 +319,10 @@ sub refresh () { #{{{
 	# check for added or removed pages
 	foreach my $file (@files) {
 		my $page=pagename($file);
+		if (exists $pagesources{$page} && $pagesources{$page} ne $file) {
+			# the page has changed its type
+			$forcerebuild{$page}=1;
+		}
 		$pagesources{$page}=$file;
 		if (! $pagemtime{$page}) {
 			if (isinternal($page)) {
diff --git a/debian/changelog b/debian/changelog
index a0d526f88..cfe168825 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -22,6 +22,7 @@ ikiwiki (2.55) UNRELEASED; urgency=low
   * Split out error messages from editpage.tmpl into several separate
     templates.
   * attachment: Do not escape _ when determining attachment filenames.
+  * Rebuild pages that change their type. (Gabriel McManus)
 
  -- Joey Hess <joeyh@debian.org>  Mon, 21 Jul 2008 11:35:46 -0400
 
diff --git a/doc/bugs/htmlscrubber_undoes_email_obfuscation_by_Text::Markdown.mdwn b/doc/bugs/htmlscrubber_undoes_email_obfuscation_by_Text::Markdown.mdwn
index b010a02b3..f193efc0c 100644
--- a/doc/bugs/htmlscrubber_undoes_email_obfuscation_by_Text::Markdown.mdwn
+++ b/doc/bugs/htmlscrubber_undoes_email_obfuscation_by_Text::Markdown.mdwn
@@ -28,3 +28,10 @@ The relevant commits are on the master branch of [my "fork" of ikiwiki on Github
 --Gabriel.
 
 [github]: http://github.com/gmcmanus/ikiwiki/
+
+> Thanks for coming up with a patch, but overriding
+> `Text::Markdown::_EncodeEmailAddress` gets into its internals more than
+> I'm comfortable with.
+> 
+> It would probably be best to add an option to [[cpan Text;:Markdown]] to
+> let the email address munging be disabled. --[[Joey]]
diff --git a/doc/bugs/page_is_not_rebuilt_if_it_changes_extension.mdwn b/doc/bugs/page_is_not_rebuilt_if_it_changes_extension.mdwn
index d5719744e..e47be8d28 100644
--- a/doc/bugs/page_is_not_rebuilt_if_it_changes_extension.mdwn
+++ b/doc/bugs/page_is_not_rebuilt_if_it_changes_extension.mdwn
@@ -18,3 +18,10 @@ ikiwiki fails when trying to create a directory "a" where there is a file "a"
 (or vice versa).
 
 The same problem occurs if both "a" and "a.mdwn" exist in the wiki.
+
+> Thank you for looking into it!
+> 
+> On the use of forcerebuild, I think it's acceptable; plugins that unset
+> it would break other plugins that set it, too. 
+> 
+> [[cherry-picked|done]] --[[Joey]]
diff --git a/doc/bugs/underlaydir_file_expose.mdwn b/doc/bugs/underlaydir_file_expose.mdwn
index b8e84969c..c827c6dd8 100644
--- a/doc/bugs/underlaydir_file_expose.mdwn
+++ b/doc/bugs/underlaydir_file_expose.mdwn
@@ -1,9 +1,4 @@
 If a file in the srcdir is removed, exposing a file in the underlaydir,
-ikiwiki will not notice the change and rebuild it until the file in the
-underlaydir gets a mtime newer than the mtime the removed file had.
-
-Relatedly, if there are two files with different extensions that build a
-page with the same name, in a directory, ikiwiki will update the page
-whenever either changes, using the changed one as the source. But if that
-most recently changed one is removed, it won't rebuild the page using the
-older one as the source.
+ikiwiki will notice the removal and delete the page from the destdir. The
+page from the underlay will not be built. (However, it will be if the wiki
+gets rebuilt.)