diff --git a/history.md b/history.md
index 2055a5e..4077007 100644
--- a/history.md
+++ b/history.md
@@ -1,3 +1,7 @@
+# 1.5.0
+
+- fixed parameters managment when using hash with several values
+
 # 1.4.0
 
 - Response is no more a String, and the mixin is replaced by an abstract_response, existing calls are redirected to response body with a warning.
diff --git a/lib/restclient/payload.rb b/lib/restclient/payload.rb
index 3b2ee57..43b779a 100644
--- a/lib/restclient/payload.rb
+++ b/lib/restclient/payload.rb
@@ -58,7 +58,7 @@ module RestClient
         params.each do |key, value|
           calculated_key = parent_key ? "#{parent_key}[#{escape key}]" : escape(key)
           if value.is_a? Hash
-            result << flatten_params(value, calculated_key).flatten
+            result += flatten_params(value, calculated_key)
           elsif value.is_a? Array
             value.each do |elem|
               result << [calculated_key, elem]
@@ -67,6 +67,7 @@ module RestClient
             result << [calculated_key, value]
           end
         end
+        p result.length
         result
       end
 
diff --git a/spec/payload_spec.rb b/spec/payload_spec.rb
index 20552ce..85abaf6 100644
--- a/spec/payload_spec.rb
+++ b/spec/payload_spec.rb
@@ -21,6 +21,11 @@ describe RestClient::Payload do
               should == "foo[bar][baz]=qux"
     end
 
+    it "should handle many attributes inside a hash" do
+      parameters = RestClient::Payload::UrlEncoded.new({:foo => {:bar => 'baz', :baz => 'qux'}}).to_s
+      parameters.should include("foo[bar]=baz", "foo[baz]=qux")
+    end
+
     it "should form properly use symbols as parameters" do
       RestClient::Payload::UrlEncoded.new({:foo => :bar}).to_s.
               should == "foo=bar"