diff --git a/lib/mongo/cursor.rb b/lib/mongo/cursor.rb
index dee3a79..27896c2 100644
--- a/lib/mongo/cursor.rb
+++ b/lib/mongo/cursor.rb
@@ -282,6 +282,8 @@ module Mongo
           returning({}) do |hash|
             fields.each { |field| hash[field] = 1 }
           end
+        when Hash
+          return fields
       end
     end
 
diff --git a/test/unit/cursor_test.rb b/test/unit/cursor_test.rb
index 3be5839..178d228 100644
--- a/test/unit/cursor_test.rb
+++ b/test/unit/cursor_test.rb
@@ -30,6 +30,13 @@ class CursorTest < Test::Unit::TestCase
       assert @cursor.fields == {:name => 1, :date => 1}
     end
 
+    should "set mix fields 0 and 1" do
+      assert_nil @cursor.fields
+
+      @cursor = Cursor.new(@collection, :fields => {:name => 1, :date => 0})
+      assert @cursor.fields == {:name => 1, :date => 0}
+    end
+
     should "set limit" do
       assert_equal 0, @cursor.limit