diff --git a/ChangeLog b/ChangeLog
index 88de32cd48..7a1a66ca78 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,12 +1,12 @@
-Sat Sep  1 11:14:38 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Sat Sep  1 14:24:23 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* st.c (st_numcmp, st_numhash): use st_data_t instead of long, because
 	  the former may be larger than the latter.
 
 	* include/ruby/st.h (CHAR_BIT): get rid of magic number.
 
-	* include/ruby/st.h (struct st_table): num_entries never exceed
-	  num_bins.
+	* include/ruby/st.h (rb_index_t): use st_data_t for the platforms it
+	  is larger than int.
 
 Fri Aug 31 07:12:24 2007  NAKAMURA Usaku  <usa@ruby-lang.org>
 
diff --git a/include/ruby/st.h b/include/ruby/st.h
index 7702c7a8e9..3b64bd72fb 100644
--- a/include/ruby/st.h
+++ b/include/ruby/st.h
@@ -49,15 +49,14 @@ struct st_hash_type {
     int (*hash)(ANYARGS /*st_data_t*/);               /* st_hash_func* */
 };
 
-typedef unsigned int st_index_t;
-#define ST_INDEX_BITS (sizeof(st_index_t) * CHAR_BIT - 1)
+typedef st_data_t st_index_t;
+#define ST_INDEX_BITS (sizeof(st_index_t) * CHAR_BIT)
 
 struct st_table {
     const struct st_hash_type *type;
     unsigned int entries_packed : 1;
-    st_index_t num_bins : ST_INDEX_BITS;
-    unsigned int st_dummy_bit : 1;
-    st_index_t num_entries : ST_INDEX_BITS;
+    st_index_t num_bins : ST_INDEX_BITS - 1;
+    st_index_t num_entries;
     struct st_table_entry **bins;
     struct st_table_entry *head;
 };