diff --git a/ext/extmk.rb b/ext/extmk.rb
index a7eea62a27..98fd76ca68 100755
--- a/ext/extmk.rb
+++ b/ext/extmk.rb
@@ -83,6 +83,8 @@ end
 
 def extract_makefile(makefile, keep = true)
   m = File.read(makefile)
+  s = m[/^CLEANFILES[ \t]*=[ \t](.*)/, 1] and $cleanfiles = s.split
+  s = m[/^DISTCLEANFILES[ \t]*=[ \t](.*)/, 1] and $distcleanfiles = s.split
   if !(target = m[/^TARGET[ \t]*=[ \t]*(\S*)/, 1])
     return keep
   end
@@ -127,7 +129,6 @@ def extract_makefile(makefile, keep = true)
   end
   $objs = (m[/^OBJS[ \t]*=[ \t](.*)/, 1] || "").split
   $srcs = (m[/^SRCS[ \t]*=[ \t](.*)/, 1] || "").split
-  $distcleanfiles = (m[/^DISTCLEANFILES[ \t]*=[ \t](.*)/, 1] || "").split
   $LOCAL_LIBS = m[/^LOCAL_LIBS[ \t]*=[ \t]*(.*)/, 1] || ""
   $LIBPATH = Shellwords.shellwords(m[/^libpath[ \t]*=[ \t]*(.*)/, 1] || "") - %w[$(libdir) $(topdir)]
   true
@@ -201,7 +202,7 @@ def extmake(target)
 	$extconf_h = nil
 	ok &&= extract_makefile(makefile)
 	old_objs = $objs
-	old_cleanfiles = $distcleanfiles
+	old_cleanfiles = $distcleanfiles | $cleanfiles
 	conf = ["#{$srcdir}/makefile.rb", "#{$srcdir}/extconf.rb"].find {|f| File.exist?(f)}
 	if (!ok || ($extconf_h && !File.exist?($extconf_h)) ||
 	    !(t = modified?(makefile, MTIMES)) ||
@@ -274,7 +275,7 @@ def extmake(target)
       args += ["static"] unless $clean
       $extlist.push [$static, target, $target, $preload]
     end
-    FileUtils.rm_f(old_cleanfiles - $distcleanfiles)
+    FileUtils.rm_f(old_cleanfiles - $distcleanfiles - $cleanfiles)
     FileUtils.rm_f(old_objs - $objs)
     unless $configure_only or system($make, *args)
       $ignore or $continue or return false