diff --git a/lib/gooddata/helpers/global_helpers_params.rb b/lib/gooddata/helpers/global_helpers_params.rb
index 6b977e351..ef084ee09 100644
--- a/lib/gooddata/helpers/global_helpers_params.rb
+++ b/lib/gooddata/helpers/global_helpers_params.rb
@@ -61,6 +61,8 @@ def encode_hidden_params(params)
       def decode_params(params, options = {})
         key = ENCODED_PARAMS_KEY.to_s
         hidden_key = ENCODED_HIDDEN_PARAMS_KEY.to_s
+        raise "Mandatory parameter '#{key}' or '#{hidden_key}' of type 'HashType' needs to be specified" if params[key].nil? && params[hidden_key].nil?
+
         data_params = params[key] || '{}'
         hidden_data_params = if params.key?(hidden_key) && params[hidden_key].nil?
                                "{\"#{hidden_key}\" : null}"
diff --git a/spec/unit/helpers/global_helpers_spec.rb b/spec/unit/helpers/global_helpers_spec.rb
index 1118a487c..4866956cb 100644
--- a/spec/unit/helpers/global_helpers_spec.rb
+++ b/spec/unit/helpers/global_helpers_spec.rb
@@ -62,8 +62,8 @@
     end
 
     it 'should encode params and preserve the nil in hidden' do
-      x = GoodData::Helpers.decode_params(GoodData::Helpers::ENCODED_HIDDEN_PARAMS_KEY.to_s => nil)
-      expect(x).to eq("gd_encoded_hidden_params" => nil)
+      x = GoodData::Helpers.decode_params(GoodData::Helpers::ENCODED_HIDDEN_PARAMS_KEY.to_s => nil, GoodData::Helpers::ENCODED_PARAMS_KEY.to_s => '{"d":{"b": "c"}}')
+      expect(x).to eq({"d"=>{"b"=>"c"}, "gd_encoded_hidden_params"=>nil})
     end
 
     it 'should encode params and preserve the nil in hidden' do