diff --git a/lib/rack/attack.rb b/lib/rack/attack.rb
index 1c5c2ab..f6ab929 100644
--- a/lib/rack/attack.rb
+++ b/lib/rack/attack.rb
@@ -50,13 +50,11 @@ class Rack::Attack
     end
 
     def blocklist_ip(ip_address)
-      ip_blocklist_proc = lambda { |request| IPAddr.new(ip_address).include?(IPAddr.new(request.ip)) }
-      anonymous_blocklists << Blocklist.new(nil, &ip_blocklist_proc)
+      anonymous_blocklists << Blocklist.new(nil) { |request| IPAddr.new(ip_address).include?(IPAddr.new(request.ip)) }
     end
 
     def safelist_ip(ip_address)
-      ip_safelist_proc = lambda { |request| IPAddr.new(ip_address).include?(IPAddr.new(request.ip)) }
-      anonymous_safelists << Safelist.new(nil, &ip_safelist_proc)
+      anonymous_safelists << Safelist.new(nil) { |request| IPAddr.new(ip_address).include?(IPAddr.new(request.ip)) }
     end
 
     def throttle(name, options, &block)