diff --git a/ChangeLog b/ChangeLog
index 807c0d97e0..a7a0d15f99 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Jul  3 18:12:56 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/mkmf.rb (install_dirs): revert DESTDIR prefix by r39841, since
+	  it is fixed by r41648.  [ruby-core:55760] [Bug #8115]
+
 Wed Jul  3 14:15:25 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* dir.c (do_stat): use rb_w32_ustati64() in win32.c to get rid of
diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index 8179974034..751e190dfa 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -199,21 +199,21 @@ module MakeMakefile
       ]
     elsif $configure_args.has_key?('--vendor')
       dirs = [
-        ['BINDIR',        '$(DESTDIR)$(bindir)'],
-        ['RUBYCOMMONDIR', '$(DESTDIR)$(vendordir)$(target_prefix)'],
-        ['RUBYLIBDIR',    '$(DESTDIR)$(vendorlibdir)$(target_prefix)'],
-        ['RUBYARCHDIR',   '$(DESTDIR)$(vendorarchdir)$(target_prefix)'],
-        ['HDRDIR',        '$(DESTDIR)$(rubyhdrdir)/ruby$(target_prefix)'],
-        ['ARCHHDRDIR',    '$(DESTDIR)$(rubyhdrdir)/$(arch)/ruby$(target_prefix)'],
+        ['BINDIR',        '$(bindir)'],
+        ['RUBYCOMMONDIR', '$(vendordir)$(target_prefix)'],
+        ['RUBYLIBDIR',    '$(vendorlibdir)$(target_prefix)'],
+        ['RUBYARCHDIR',   '$(vendorarchdir)$(target_prefix)'],
+        ['HDRDIR',        '$(rubyhdrdir)/ruby$(target_prefix)'],
+        ['ARCHHDRDIR',    '$(rubyhdrdir)/$(arch)/ruby$(target_prefix)'],
       ]
     else
       dirs = [
-        ['BINDIR',        '$(DESTDIR)$(bindir)'],
-        ['RUBYCOMMONDIR', '$(DESTDIR)$(sitedir)$(target_prefix)'],
-        ['RUBYLIBDIR',    '$(DESTDIR)$(sitelibdir)$(target_prefix)'],
-        ['RUBYARCHDIR',   '$(DESTDIR)$(sitearchdir)$(target_prefix)'],
-        ['HDRDIR',        '$(DESTDIR)$(rubyhdrdir)/ruby$(target_prefix)'],
-        ['ARCHHDRDIR',    '$(DESTDIR)$(rubyhdrdir)/$(arch)/ruby$(target_prefix)'],
+        ['BINDIR',        '$(bindir)'],
+        ['RUBYCOMMONDIR', '$(sitedir)$(target_prefix)'],
+        ['RUBYLIBDIR',    '$(sitelibdir)$(target_prefix)'],
+        ['RUBYARCHDIR',   '$(sitearchdir)$(target_prefix)'],
+        ['HDRDIR',        '$(rubyhdrdir)/ruby$(target_prefix)'],
+        ['ARCHHDRDIR',    '$(rubyhdrdir)/$(arch)/ruby$(target_prefix)'],
       ]
     end
     dirs << ['target_prefix', (target_prefix ? "/#{target_prefix}" : "")]
@@ -1770,7 +1770,6 @@ SRC
   # :stopdoc:
 
   def with_destdir(dir)
-    return dir unless $extmk
     dir = dir.sub($dest_prefix_pattern, '')
     /\A\$[\(\{]/ =~ dir ? dir : "$(DESTDIR)"+dir
   end