diff --git a/ChangeLog b/ChangeLog
index e2c63838bc..3d123bdde3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Aug 31 23:59:03 2006  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/mkmf.rb (configuration): follow nil.to_s.
+
 Thu Aug 31 20:50:46 2006  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* lib/mkmf.rb (create_makefile): follow nil.to_s.
@@ -151,7 +155,7 @@ Tue Aug 22 18:47:51 2006  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* lib/rdoc/parsers/parse_c.rb (RDoc::C_Parser::handle_method):
 	  rdoc documents C module methods as instance methods. a patch in
-	  [ruby-core:08536]. 
+	  [ruby-core:08536].
 
 Tue Aug 22 12:35:57 2006  NARUSE, Yui  <naruse@ruby-lang.org>
 
diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index b9f04c4f20..173c1981c2 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -1073,7 +1073,7 @@ LIBRUBYARG_SHARED = #$LIBRUBYARG_SHARED
 LIBRUBYARG_STATIC = #$LIBRUBYARG_STATIC
 
 RUBY_EXTCONF_H = #{$extconf_h}
-CFLAGS   = #{CONFIG['CCDLFLAGS'] unless $static} #$CFLAGS #$ARCH_FLAG
+CFLAGS   = #{$static ? '' : CONFIG['CCDLFLAGS']} #$CFLAGS #$ARCH_FLAG
 INCFLAGS = -I. #$INCFLAGS
 CPPFLAGS = #{extconf_h}#{$CPPFLAGS}
 CXXFLAGS = $(CFLAGS) #{CONFIG['CXXFLAGS']}
@@ -1194,6 +1194,7 @@ def create_makefile(target, srcprefix = nil)
       deffile = "$(TARGET)-$(arch).def"
     end
   end
+  origdef ||= ''
 
   if $extmk and not $extconf_h
     create_header
@@ -1335,7 +1336,7 @@ site-install-rb: install-rb
   end
   mfile.print "\n\n"
   if makedef
-    mfile.print "$(DEFFILE): #{origdef || ''}\n"
+    mfile.print "$(DEFFILE): #{origdef}\n"
     mfile.print "\t$(RUBY) #{makedef} #{origdef} > $@\n\n"
   end