diff --git a/README.md b/README.md
index 35969b68..2e0324f9 100644
--- a/README.md
+++ b/README.md
@@ -23,10 +23,10 @@ gem install ldclient-rb
 require 'ldclient-rb'
 ```
 
-2. Create a new LDClient with your API key:
+2. Create a new LDClient with your SDK key:
 
 ```ruby
-client = LaunchDarkly::LDClient.new("your_api_key")
+client = LaunchDarkly::LDClient.new("your_sdk_key")
 ```
 
 ### Ruby on Rails
@@ -36,7 +36,7 @@ client = LaunchDarkly::LDClient.new("your_api_key")
 1.  Initialize the launchdarkly client in `config/initializers/launchdarkly.rb`:
 
 ```ruby
-Rails.configuration.ld_client = LaunchDarkly::LDClient.new("your_api_key")
+Rails.configuration.ld_client = LaunchDarkly::LDClient.new("your_sdk_key")
 ```
 
 2.  You may want to include a function in your ApplicationController
diff --git a/lib/ldclient-rb/evaluation.rb b/lib/ldclient-rb/evaluation.rb
index 03b1ee3d..90df5159 100644
--- a/lib/ldclient-rb/evaluation.rb
+++ b/lib/ldclient-rb/evaluation.rb
@@ -118,7 +118,7 @@ def eval_internal(flag, user, store, events)
             begin
               prereq_res = eval_internal(prereq_flag, user, store, events)
               variation = get_variation(prereq_flag, prerequisite[:variation])
-              events.push(kind: "feature", key: prereq_flag[:key], value: prereq_res)
+              events.push(kind: "feature", key: prereq_flag[:key], value: prereq_res, version: prereq_flag[:version], prereqOf: flag[:key])
               if prereq_res.nil? || prereq_res!= variation
                 failed_prereq = true
               end
diff --git a/lib/ldclient-rb/ldclient.rb b/lib/ldclient-rb/ldclient.rb
index d28323c1..1af095e5 100644
--- a/lib/ldclient-rb/ldclient.rb
+++ b/lib/ldclient-rb/ldclient.rb
@@ -114,26 +114,32 @@ def variation(key, user, default)
       sanitize_user(user)
       feature = @store.get(key)
 
-        begin
-          res = evaluate(feature, user, @store)
-          if !res[:events].nil?
-            res[:events].each do |event|
-              @event_processor.add_event(event)
-            end
-          end
-          if !res[:value].nil?
-            @event_processor.add_event(kind: "feature", key: key, user: user, value: res[:value], default: default)
-            return res[:value]
-          else
-            @config.logger.debug("[LDClient] Result value is null in toggle")
-            @event_processor.add_event(kind: "feature", key: key, user: user, value: default, default: default)        
-            return default            
+      if feature.nil?
+        @config.logger.error("[LDClient] Unknown feature flag #{key}. Returning default value")
+        @event_processor.add_event(kind: "feature", key: key, value: default, default: default)
+        return default
+      end
+
+      begin
+        res = evaluate(feature, user, @store)
+        if !res[:events].nil?
+          res[:events].each do |event|
+            @event_processor.add_event(event)
           end
-        rescue => exn
-          @config.logger.warn("[LDClient] Error evaluating feature flag: #{exn.inspect}. \nTrace: #{exn.backtrace}")
-          @event_processor.add_event(kind: "feature", key: key, user: user, value: default, default: default)
-          return default
         end
+        if !res[:value].nil?
+          @event_processor.add_event(kind: "feature", key: key, user: user, value: res[:value], default: default, version: feature[:version])
+          return res[:value]
+        else
+          @config.logger.debug("[LDClient] Result value is null in toggle")
+          @event_processor.add_event(kind: "feature", key: key, user: user, value: default, default: default, version: feature[:version])        
+          return default            
+        end
+      rescue => exn
+        @config.logger.warn("[LDClient] Error evaluating feature flag: #{exn.inspect}. \nTrace: #{exn.backtrace}")
+        @event_processor.add_event(kind: "feature", key: key, user: user, value: default, default: default, version: feature[:version])
+        return default
+      end
     end
 
     #
diff --git a/lib/ldclient-rb/requestor.rb b/lib/ldclient-rb/requestor.rb
index 16e1d34e..69a1ac98 100644
--- a/lib/ldclient-rb/requestor.rb
+++ b/lib/ldclient-rb/requestor.rb
@@ -32,7 +32,7 @@ def make_request(path)
       end
 
       if res.status == 401
-        @config.logger.error("[LDClient] Invalid API key")
+        @config.logger.error("[LDClient] Invalid SDK key")
         return nil
       end