diff --git a/ChangeLog b/ChangeLog
index b69568df5d..086091a8c3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jan 12 12:33:56 2009  Tanaka Akira  <akr@fsij.org>
+
+	* ext/socket/mkconstants.rb: don't use bytesize because 1.9 dependent.
+	  [ruby-core:21266]
+
 Mon Jan 12 10:39:19 2009  Koichi Sasada  <ko1@atdot.net>
 
 	* thread.c: fix comment (terminology: Global VM Lock).
diff --git a/ext/socket/mkconstants.rb b/ext/socket/mkconstants.rb
index 518618c45e..84d42652a6 100644
--- a/ext/socket/mkconstants.rb
+++ b/ext/socket/mkconstants.rb
@@ -177,7 +177,7 @@ ERB.new(<<'EOS', nil, '%').def_method(Object, "gen_int_to_name_hash(hash_var, pa
     <%=hash_var%> = st_init_numtable();
 % reverse_each_name_with_prefix_optional(pat, prefix_pat) {|n,s|
 #ifdef <%=n%>
-    st_insert(<%=hash_var%>, (st_data_t)<%=n%>, (st_data_t)rb_intern2(<%=c_str s%>, <%=s.bytesize%>));
+    st_insert(<%=hash_var%>, (st_data_t)<%=n%>, (st_data_t)rb_intern2(<%=c_str s%>, <%=s.length%>));
 #endif
 % }
 EOS