diff --git a/lib/ldclient-rb/ldclient.rb b/lib/ldclient-rb/ldclient.rb
index 3b004485..9c72d2f9 100644
--- a/lib/ldclient-rb/ldclient.rb
+++ b/lib/ldclient-rb/ldclient.rb
@@ -5,6 +5,9 @@
 require 'logger'
 
 module LaunchDarkly
+
+  BUILTINS = [:key, :ip, :country, :email, :firstName, :lastName, :avatar, :name]
+
   # 
   # A client for the LaunchDarkly API. Client instances are thread-safe. Users 
   # should create a single client instance for the lifetime of the application.
@@ -221,7 +224,7 @@ def param_for_user(feature, user)
     def match_target?(target, user)
       attrib = target[:attribute].to_sym
 
-      if attrib == :key or attrib == :ip or attrib == :country
+      if BUILTINS.include?(attrib)
         if user[attrib]
           u_value = user[attrib]
           return target[:values].include? u_value
@@ -247,8 +250,19 @@ def match_target?(target, user)
 
     end
 
+    def match_user?(variation, user)
+      if !!variation[:userTarget]
+        return match_target?(variation[:userTarget], user)
+      end
+      return false
+    end
+
     def match_variation?(variation, user)
       variation[:targets].each do |target|
+        if !!variation[:userTarget] and target[:attribute].to_sym == :key
+          next
+        end
+
         if match_target?(target, user)
           return true
         end
@@ -267,6 +281,12 @@ def evaluate(feature, user)
         return nil
       end
 
+      feature[:variations].each do |variation|
+        if match_user?(variation, user)
+          return variation[:value]
+        end
+      end
+
       feature[:variations].each do |variation|
         if match_variation?(variation, user)
           return variation[:value]
@@ -286,7 +306,7 @@ def evaluate(feature, user)
 
     end
 
-    private :add_event, :get_flag_int, :param_for_user, :match_target?, :match_variation?, :evaluate, :create_worker
+    private :add_event, :get_flag_int, :param_for_user, :match_target?, :match_user?, :match_variation?, :evaluate, :create_worker
 
 
   end