diff --git a/lib/mongo/collection.rb b/lib/mongo/collection.rb
index d014ad4..c65fcee 100644
--- a/lib/mongo/collection.rb
+++ b/lib/mongo/collection.rb
@@ -628,7 +628,12 @@ module Mongo
       if raw
         result
       elsif result["result"]
-        @db[result["result"]]
+        if result['result'].is_a? BSON::OrderedHash and result['result'].has_key? 'db' and result['result'].has_key? 'collection'
+          otherdb = @db.connection[result['result']['db']]
+          otherdb[result['result']['collection']]
+        else
+          @db[result["result"]]
+        end
       else
         raise ArgumentError, "Could not instantiate collection from result. If you specified " +
           "{:out => {:inline => true}}, then you must also specify :raw => true to get the results."
diff --git a/test/collection_test.rb b/test/collection_test.rb
index 9b04456..ed90ca7 100644
--- a/test/collection_test.rb
+++ b/test/collection_test.rb
@@ -559,6 +559,19 @@ class TestCollection < Test::Unit::TestCase
         @@test.map_reduce(m, r, :raw => true, :out => {:inline => 1})
         assert res["results"]
       end
+      
+      def test_map_reduce_with_collection_output_to_other_db
+        @@test << {:user_id => 1}
+        @@test << {:user_id => 2}
+        
+        m = Code.new("function() { emit(this.user_id, 1); }")
+        r = Code.new("function(k,vals) { return 1; }")
+        res = @@test.map_reduce(m, r, :out => {:replace => 'foo', :db => 'somedb'})
+        assert res["result"]
+        assert res["counts"]
+        assert res["timeMillis"]
+        assert res.find.to_a.any? {|doc| doc["_id"] == 2 && doc["value"] == 1}
+      end
     end
   end