diff --git a/lib/mongo/collection.rb b/lib/mongo/collection.rb
index 78d426a..7d04b7f 100644
--- a/lib/mongo/collection.rb
+++ b/lib/mongo/collection.rb
@@ -235,30 +235,37 @@ module Mongo
 
     # Update a single document in this collection.
     #
-    # :spec :: a hash specifying elements which must be present for
-    #   a document to be updated
+    # :selector :: a hash specifying elements which must be present for a document to be updated. Note: 
+    # the update command currently updates only the first document matching the
+    # given selector. If you want all matching documents to be updated, be sure
+    # to specify :multi => true.
     # :document :: a hash specifying the fields to be changed in the
-    #   selected document, or (in the case of an upsert) the document to
-    #   be inserted
+    # selected document, or (in the case of an upsert) the document to
+    # be inserted
     #
     # Options:
     # :upsert :: if true, perform an upsert operation
+    # :multi :: update all documents matching the selector, as opposed to
+    # just the first matching document. Note: only works in 1.1.3 or later.
     # :safe :: if true, check that the update succeeded. OperationFailure
-    #   will be raised on an error. Checking for safety requires an extra
-    #   round-trip to the database
-    def update(spec, document, options={})
+    # will be raised on an error. Checking for safety requires an extra
+    # round-trip to the database
+    def update(selector, document, options={})
       message = ByteBuffer.new
       message.put_int(0)
       BSON.serialize_cstr(message, "#{@db.name}.#{@name}")
-      message.put_int(options[:upsert] ? 1 : 0) # 1 if a repsert operation (upsert)
-      message.put_array(BSON.new.serialize(spec, false).to_a)
+      update_options  = 0
+      update_options += 1 if options[:upsert]
+      update_options += 2 if options[:multi]
+      message.put_int(update_options)
+      message.put_array(BSON.new.serialize(selector, false).to_a)
       message.put_array(BSON.new.serialize(document, false).to_a)
       if options[:safe]
         @db.send_message_with_safe_check(Mongo::Constants::OP_UPDATE, message,
-          "db.#{@name}.update(#{spec.inspect}, #{document.inspect})")
+          "db.#{@name}.update(#{selector.inspect}, #{document.inspect})")
       else
         @db.send_message_with_operation(Mongo::Constants::OP_UPDATE, message, 
-          "db.#{@name}.update(#{spec.inspect}, #{document.inspect})")
+          "db.#{@name}.update(#{selector.inspect}, #{document.inspect})")
       end
     end
 
diff --git a/lib/mongo/db.rb b/lib/mongo/db.rb
index 0540984..23cc0c7 100644
--- a/lib/mongo/db.rb
+++ b/lib/mongo/db.rb
@@ -465,7 +465,7 @@ module Mongo
       end
     end
 
-    # Note: this method is a stub. Will be completed in an upcoming refactoring.
+    # Send a message to the database and wait for the response.
     def receive_message_with_operation(operation, message, log_message=nil)
       message_with_headers = add_message_headers(operation, message).to_s
       @logger.debug("  MONGODB #{log_message || message}") if @logger
diff --git a/test/test_collection.rb b/test/test_collection.rb
index a83325c..5f3aa4b 100644
--- a/test/test_collection.rb
+++ b/test/test_collection.rb
@@ -97,6 +97,20 @@ class TestCollection < Test::Unit::TestCase
     assert_equal 1, @@test.find_one(:_id => id2)["x"]
   end
 
+  if @@version >= "1.1.3"
+    def test_multi_update
+      @@test.save("num" => 10)
+      @@test.save("num" => 10)
+      @@test.save("num" => 10)
+      assert_equal 3, @@test.count
+
+      @@test.update({"num" => 10}, {"$set" => {"num" => 100}}, :multi => true)
+      @@test.find.each do |doc|
+        assert_equal 100, doc["num"]
+      end
+    end
+  end
+
   def test_upsert
     @@test.update({"page" => "/"}, {"$inc" => {"count" => 1}}, :upsert => true)
     @@test.update({"page" => "/"}, {"$inc" => {"count" => 1}}, :upsert => true)
diff --git a/test/unit/collection_test.rb b/test/unit/collection_test.rb
index da7506d..2d8c0e8 100644
--- a/test/unit/collection_test.rb
+++ b/test/unit/collection_test.rb
@@ -38,7 +38,6 @@ class CollectionTest < Test::Unit::TestCase
         op == 2001 && log.include?("db.books.update")
       end
       @coll.update({}, {:title => 'Moby Dick'}, :safe => true)
-
     end
 
     should "send safe insert message" do