diff --git a/ChangeLog b/ChangeLog
index 5ad2d12977..bd20b47286 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Fri May  3 13:29:11 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* include/ruby/win32.h (INTPTR_MAX, INTPTR_MIN, UINTPTR_MAX): also
+	  should be defined when defining intptr_t and uintptr_t.
+	  bigdecimal.c requires the former two now.
+
 Fri May  3 13:22:12 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* win32/win32.c (poll_child_status): fix build error on older mingw.
diff --git a/include/ruby/win32.h b/include/ruby/win32.h
index 56fa3e5c0c..fe8613f299 100644
--- a/include/ruby/win32.h
+++ b/include/ruby/win32.h
@@ -80,16 +80,21 @@ extern "C++" {			/* template without extern "C++" */
 # if !defined(_INTPTR_T_DEFINED)
 #  ifdef _WIN64
 typedef __int64 intptr_t;
+#    define INTPTR_MAX 9223372036854775807I64
 #  else
 typedef int intptr_t;
+#    define INTPTR_MAX 2147483647
 #  endif
+#  define INTPTR_MIN (-INTPTR_MAX-1)
 #  define _INTPTR_T_DEFINED
 # endif
 # if !defined(_UINTPTR_T_DEFINED)
 #  ifdef _WIN64
 typedef unsigned __int64 uintptr_t;
+#    define UINTPTR_MAX 18446744073709551615UI64
 #  else
 typedef unsigned int uintptr_t;
+#    define UINTPTR_MAX 4294967295U
 #  endif
 #  define _UINTPTR_T_DEFINED
 # endif