diff --git a/lib/yinx/note_meta.rb b/lib/yinx/note_meta.rb
index <HASH>..<HASH> 100644
--- a/lib/yinx/note_meta.rb
+++ b/lib/yinx/note_meta.rb
@@ -5,12 +5,11 @@ class NoteMeta
   [:updated, :created, :title, :notebookGuid, :guid, :contentLength, :tagGuids].each do |method|
     define_method method do
       iv_name = "@#{method}"
-      value = instance_variable_get iv_name
-      unless value
+      unless instance_variable_defined? iv_name
         value = instance_variable_get("@meta").send method
         instance_variable_set iv_name, value
       end
-      value
+      instance_variable_get iv_name
     end
   end
 
diff --git a/lib/yinx/version.rb b/lib/yinx/version.rb
index <HASH>..<HASH> 100644
--- a/lib/yinx/version.rb
+++ b/lib/yinx/version.rb
@@ -1,3 +1,3 @@
 module Yinx
-  VERSION = "0.1.2"
+  VERSION = "0.1.3"
 end
fix bug: tagGuids maybe nil, use `instance_variable_defined?` instead of `unless` to detect it