diff --git a/lib/twitter/client.rb b/lib/twitter/client.rb
index 43c566359..8d03fea9e 100644
--- a/lib/twitter/client.rb
+++ b/lib/twitter/client.rb
@@ -40,13 +40,13 @@ module Twitter
   # @note All methods have been separated into modules and follow the same grouping used in {http://dev.twitter.com/doc the Twitter API Documentation}.
   # @see http://dev.twitter.com/pages/every_developer
   class Client
-
     include Twitter::Authenticatable
     include Twitter::Connection
     include Twitter::Request
-
     attr_accessor *Config::VALID_OPTIONS_KEYS
 
+    MAX_USERS_PER_REQUEST = 100
+
     # Initializes a new API object
     #
     # @param attrs [Hash]
@@ -2402,11 +2402,11 @@ def update_with_media(status, image, options={})
     #     Twitter.users(7505382, 14100886)    # Same as above
     def users(*args)
       options = args.last.is_a?(Hash) ? args.pop : {}
-      users = args
-      options.merge_users!(Array(users))
-      get("/1/users/lookup.json", options).map do |user|
-        Twitter::User.new(user)
-      end
+      args.each_slice(MAX_USERS_PER_REQUEST).threaded_map do |users|
+        get("/1/users/lookup.json", options.merge_users(Array(users))).map do |user|
+          Twitter::User.new(user)
+        end
+      end.flatten
     end
 
     # Access the profile image in various sizes for the user with the indicated screen name
diff --git a/lib/twitter/core_ext/hash.rb b/lib/twitter/core_ext/hash.rb
index 18ef87697..e0fa714bb 100644
--- a/lib/twitter/core_ext/hash.rb
+++ b/lib/twitter/core_ext/hash.rb
@@ -92,6 +92,14 @@ def merge_user!(user, prefix=nil, suffix=nil)
     self
   end
 
+  # Take a multiple users and merge them into the hash with the correct keys
+  #
+  # @param users [Array<Integer, String, Twitter::User>, Set<Integer, String, Twitter::User>] An array of Twitter user IDs, screen_names, or objects.
+  # @return [Hash]
+  def merge_users(*users)
+    self.dup.merge_users!(users)
+  end
+
   # Take a multiple users and merge them into the hash with the correct keys
   #
   # @param users [Array<Integer, String, Twitter::User>, Set<Integer, String, Twitter::User>] An array of Twitter user IDs, screen_names, or objects.