diff --git a/ChangeLog b/ChangeLog
index d3b20624c7..518879b228 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Mon Mar  5 12:43:43 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* st.c (unpack_entries): reallocate bins if packed array size
+	  is not same as initial bins size.  based on a patch by
+	  Sokolov Yura <funny.falcon AT gmail.com>.
+
 Mon Mar  5 11:51:48 2012  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* ext/bigdecimal/lib/bigdecimal/math.rb: remove description about
diff --git a/st.c b/st.c
index f40ad33c8c..9c4a19fdd2 100644
--- a/st.c
+++ b/st.c
@@ -478,7 +478,12 @@ unpack_entries(register st_table *table)
     table->bins = (st_table_entry **)&packed_bins;
     tmp_table.entries_packed = 0;
     tmp_table.num_entries = 0;
+#if ST_DEFAULT_INIT_TABLE_SIZE == ST_DEFAULT_PACKED_TABLE_SIZE
     MEMZERO(tmp_table.bins, st_table_entry*, tmp_table.num_bins);
+#else
+    tmp_table.bins = st_realloc_bins(tmp_table.bins, ST_DEFAULT_INIT_TABLE_SIZE, tmp_table.num_bins);
+    tmp_table.num_bins = ST_DEFAULT_INIT_TABLE_SIZE;
+#endif
     for (i = 0; i < table->num_entries; i++) {
 	/* packed table should be numhash */
 	st_index_t key = PKEY(table, i), value = PVAL(table, i);