README.md in seventeen_mon-0.0.5 vs README.md in seventeen_mon-0.0.6

@@ -1,9 +1,13 @@
 # SeventeenMon
 
 SeventeenMon simply help you find location by IP address. Data is totally based on [17MON.CN](http://tool.17mon.cn/).
 
 
+## Compatibility
+
+I have tested it on Ruby >= 1.9.3. Other versions are not tested but should work on well. Please contact me if not.
+
 ## Installation
 
 Add this line to your application's Gemfile:
 
     gem 'seventeen_mon', git: "[e-mail]:mycolorway/SeventeenMon.git"
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