diff --git a/ChangeLog b/ChangeLog
index 20071992cc..a63590fcc7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,11 @@ Mon Jul 10 09:29:12 2006  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 	* eval.c (rb_clear_cache_for_undef): clear entries for included
 	  module.  fixed: [ruby-core:08180]
 
+Mon Jul 10 01:48:38 2006  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* st.h (st_data_t): use pointer sized integer for st_data_t.
+	  [ruby-dev:28988]
+
 Sun Jul  9 18:06:47 2006  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/mkmf.rb (try_constant): fix for value 1 at cross compiling.
diff --git a/st.h b/st.h
index 5901bd4f80..fb56f5ffad 100644
--- a/st.h
+++ b/st.h
@@ -6,7 +6,14 @@
 
 #define ST_INCLUDED
 
+#if SIZEOF_LONG == SIZEOF_VOIDP
 typedef unsigned long st_data_t;
+#elif SIZEOF_LONG_LONG == SIZEOF_VOIDP
+typedef unsigned LONG_LONG st_data_t;
+#else
+# error ---->> st.c requires sizeof(void*) == sizeof(long) to be compiled. <<---
+-
+#endif
 #define ST_DATA_T_DEFINED
 
 typedef struct st_table st_table;