diff --git a/ChangeLog b/ChangeLog
index 9fad07f19e..7c3c066519 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Dec  4 07:46:48 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/mkmf.rb (String#tr_cpp): substitute * with P like as
+	  autconf.
+
 Fri Dec  3 22:36:45 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* vm_insnhelper.c (vm_call_method): protected methods should be
diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index 4d843b67d7..71647b1816 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -184,7 +184,7 @@ class String
 
   # Generates a string used as cpp macro name.
   def tr_cpp
-    strip.upcase.tr_s("^A-Z0-9_", "_")
+    strip.upcase.tr_s("^A-Z0-9_*", "_").tr_s("*", "P")
   end
 end
 class Array