README.rdoc in knife-ec2-0.5.6 vs README.rdoc in knife-ec2-0.5.8

@@ -4,9 +4,13 @@
 
 This is the official Opscode Knife plugin for EC2. This plugin gives knife the ability to create, bootstrap, and manage EC2 instances.
 
 = INSTALLATION:
 
+Be sure you are running the latest version Chef. Versions earlier than 0.10.0 don't support plugins:
+
+    gem install chef
+
 This plugin is distributed as a Ruby Gem. To install it, run:
 
     gem install knife-ec2
 
 Depending on your system's configuration, you may need to run this command with root privileges.