diff --git a/ChangeLog b/ChangeLog
index 98c603cc35..606c3d4f2a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Jul 29 20:28:56 2011  Tanaka Akira  <akr@fsij.org>
+
+	* ext/socket/mkconstants.rb: use whitespaces as a separator.
+
 Fri Jul 29 18:59:07 2011  Tanaka Akira  <akr@fsij.org>
 
 	* ext/socket/mkconstants.rb: add documents for constants.
diff --git a/ext/socket/mkconstants.rb b/ext/socket/mkconstants.rb
index b772648cce..96370fa64e 100644
--- a/ext/socket/mkconstants.rb
+++ b/ext/socket/mkconstants.rb
@@ -40,7 +40,7 @@ h = {}
 COMMENTS = Hash.new { |h, name| h[name] = name }
 
 DATA.each_line {|s|
-  name, default_value, comment = s.chomp.split "\t"
+  name, default_value, comment = s.chomp.split(/\s+/, 3)
   next unless name && name[0] != ?#
 
   default_value = nil if default_value == 'nil'