diff --git a/Rakefile b/Rakefile
index 5f7e9e0..300ec21 100644
--- a/Rakefile
+++ b/Rakefile
@@ -10,7 +10,6 @@ namespace :test do
 
   Rake::TestTask.new(:integration) do |t|
     t.pattern = "spec/integration/*_spec.rb"
-    t.warning = false
   end
 end
 
diff --git a/lib/rack/attack/store_proxy.rb b/lib/rack/attack/store_proxy.rb
index 4d69853..de0bc0c 100644
--- a/lib/rack/attack/store_proxy.rb
+++ b/lib/rack/attack/store_proxy.rb
@@ -20,7 +20,10 @@ module Rack
         # We also want to use the underlying Dalli client instead of ::ActiveSupport::Cache::MemCacheStore,
         # and the MemCache client if using Rails 3.x
 
-        client = store.instance_variable_get(:@data)
+        if store.instance_variable_defined?(:@data)
+          client = store.instance_variable_get(:@data)
+        end
+
         if ACTIVE_SUPPORT_WRAPPER_CLASSES.include?(store.class.to_s) && ACTIVE_SUPPORT_CLIENTS.include?(client.class.to_s)
           client
         else