diff --git a/ChangeLog b/ChangeLog
index 0fbca60a39..2381f2a9a2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Mar 30 19:46:00 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ext/psych/lib: moved external library dependent files from lib.
+	  [ruby-core:29129]
+
 Tue Mar 30 18:25:52 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* file.c (rb_file_dirname): split from rb_file_s_dirname.
diff --git a/lib/psych.rb b/ext/psych/lib/psych.rb
similarity index 100%
rename from lib/psych.rb
rename to ext/psych/lib/psych.rb
diff --git a/lib/psych/coder.rb b/ext/psych/lib/psych/coder.rb
similarity index 100%
rename from lib/psych/coder.rb
rename to ext/psych/lib/psych/coder.rb
diff --git a/lib/psych/core_ext.rb b/ext/psych/lib/psych/core_ext.rb
similarity index 100%
rename from lib/psych/core_ext.rb
rename to ext/psych/lib/psych/core_ext.rb
diff --git a/lib/psych/emitter.rb b/ext/psych/lib/psych/emitter.rb
similarity index 100%
rename from lib/psych/emitter.rb
rename to ext/psych/lib/psych/emitter.rb
diff --git a/lib/psych/handler.rb b/ext/psych/lib/psych/handler.rb
similarity index 100%
rename from lib/psych/handler.rb
rename to ext/psych/lib/psych/handler.rb
diff --git a/lib/psych/nodes.rb b/ext/psych/lib/psych/nodes.rb
similarity index 100%
rename from lib/psych/nodes.rb
rename to ext/psych/lib/psych/nodes.rb
diff --git a/lib/psych/nodes/alias.rb b/ext/psych/lib/psych/nodes/alias.rb
similarity index 100%
rename from lib/psych/nodes/alias.rb
rename to ext/psych/lib/psych/nodes/alias.rb
diff --git a/lib/psych/nodes/document.rb b/ext/psych/lib/psych/nodes/document.rb
similarity index 100%
rename from lib/psych/nodes/document.rb
rename to ext/psych/lib/psych/nodes/document.rb
diff --git a/lib/psych/nodes/mapping.rb b/ext/psych/lib/psych/nodes/mapping.rb
similarity index 100%
rename from lib/psych/nodes/mapping.rb
rename to ext/psych/lib/psych/nodes/mapping.rb
diff --git a/lib/psych/nodes/node.rb b/ext/psych/lib/psych/nodes/node.rb
similarity index 100%
rename from lib/psych/nodes/node.rb
rename to ext/psych/lib/psych/nodes/node.rb
diff --git a/lib/psych/nodes/scalar.rb b/ext/psych/lib/psych/nodes/scalar.rb
similarity index 100%
rename from lib/psych/nodes/scalar.rb
rename to ext/psych/lib/psych/nodes/scalar.rb
diff --git a/lib/psych/nodes/sequence.rb b/ext/psych/lib/psych/nodes/sequence.rb
similarity index 100%
rename from lib/psych/nodes/sequence.rb
rename to ext/psych/lib/psych/nodes/sequence.rb
diff --git a/lib/psych/nodes/stream.rb b/ext/psych/lib/psych/nodes/stream.rb
similarity index 100%
rename from lib/psych/nodes/stream.rb
rename to ext/psych/lib/psych/nodes/stream.rb
diff --git a/lib/psych/omap.rb b/ext/psych/lib/psych/omap.rb
similarity index 100%
rename from lib/psych/omap.rb
rename to ext/psych/lib/psych/omap.rb
diff --git a/lib/psych/parser.rb b/ext/psych/lib/psych/parser.rb
similarity index 100%
rename from lib/psych/parser.rb
rename to ext/psych/lib/psych/parser.rb
diff --git a/lib/psych/scalar_scanner.rb b/ext/psych/lib/psych/scalar_scanner.rb
similarity index 100%
rename from lib/psych/scalar_scanner.rb
rename to ext/psych/lib/psych/scalar_scanner.rb
diff --git a/lib/psych/set.rb b/ext/psych/lib/psych/set.rb
similarity index 100%
rename from lib/psych/set.rb
rename to ext/psych/lib/psych/set.rb
diff --git a/lib/psych/tree_builder.rb b/ext/psych/lib/psych/tree_builder.rb
similarity index 100%
rename from lib/psych/tree_builder.rb
rename to ext/psych/lib/psych/tree_builder.rb
diff --git a/lib/psych/visitors.rb b/ext/psych/lib/psych/visitors.rb
similarity index 100%
rename from lib/psych/visitors.rb
rename to ext/psych/lib/psych/visitors.rb
diff --git a/lib/psych/visitors/emitter.rb b/ext/psych/lib/psych/visitors/emitter.rb
similarity index 100%
rename from lib/psych/visitors/emitter.rb
rename to ext/psych/lib/psych/visitors/emitter.rb
diff --git a/lib/psych/visitors/json_tree.rb b/ext/psych/lib/psych/visitors/json_tree.rb
similarity index 100%
rename from lib/psych/visitors/json_tree.rb
rename to ext/psych/lib/psych/visitors/json_tree.rb
diff --git a/lib/psych/visitors/to_ruby.rb b/ext/psych/lib/psych/visitors/to_ruby.rb
similarity index 100%
rename from lib/psych/visitors/to_ruby.rb
rename to ext/psych/lib/psych/visitors/to_ruby.rb
diff --git a/lib/psych/visitors/visitor.rb b/ext/psych/lib/psych/visitors/visitor.rb
similarity index 100%
rename from lib/psych/visitors/visitor.rb
rename to ext/psych/lib/psych/visitors/visitor.rb
diff --git a/lib/psych/visitors/yaml_tree.rb b/ext/psych/lib/psych/visitors/yaml_tree.rb
similarity index 100%
rename from lib/psych/visitors/yaml_tree.rb
rename to ext/psych/lib/psych/visitors/yaml_tree.rb