diff --git a/Gemfile b/Gemfile
index 2114db4a8..7b151dc5f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -14,8 +14,8 @@ group :development do
   gem 'coveralls', '~> 0.7.11'
   gem 'rubocop', '~> 0.29'
   gem 'launchy', '~> 2.4'
-  gem 'dotenv'
-  gem 'pry-doc'
+  gem 'dotenv', '~> 2.0'
+  gem 'fakefs', '~> 0.6', require: "fakefs/safe"
 end
 
 platforms :jruby do
@@ -29,7 +29,8 @@ platforms :ruby do
     gem 'yard', '~> 0.8'
     gem 'redcarpet', '~> 3.2'
     gem 'github-markup', '~> 1.3'
-    gem 'pry-byebug'
+    gem 'pry-doc', '~> 0.8'
+    gem 'pry-byebug', '~> 3.2'
   end
 end
 
diff --git a/spec/google/api_client/client_secrets_spec.rb b/spec/google/api_client/client_secrets_spec.rb
index 822a1ff9f..cf135e369 100644
--- a/spec/google/api_client/client_secrets_spec.rb
+++ b/spec/google/api_client/client_secrets_spec.rb
@@ -48,6 +48,13 @@ RSpec.describe Google::APIClient::ClientSecrets do
         expect(hash["installed"]["client_secret"]).to be == 'i8YaXdGgiQ4_KrTVNGsB7QP1'
       end
 
+      it 'should remove empty value' do
+        expect(hash["installed"]["redirect_uris"]).to be nil
+      end
+
+      it 'should remove nil values' do
+        expect(hash["installed"]["issued_at"]).to be nil
+      end
     end
   end
 
@@ -72,4 +79,12 @@ RSpec.describe Google::APIClient::ClientSecrets do
       expect(secrets.client_id).to be == '898243283568.apps.googleusercontent.com'
     end
   end
+
+  context 'with folder wihout client_secrets.json' do
+    it "should raise exception", fakefs: true do
+      FileUtils.mkdir("/tmp")
+      expect { Google::APIClient::ClientSecrets.load('/tmp') }.to raise_exception(ArgumentError)
+    end
+  end
+
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 0e2565734..af3803ef0 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -43,6 +43,7 @@ end
 
 require 'rspec'
 require 'webmock/rspec'
+require 'fakefs/spec_helpers'
 require 'json_spec'
 require 'logging'
 require 'rspec/logging_helper'
@@ -53,6 +54,7 @@ require 'google/apis/core/base_service'
 # logs will be stored in the @log_output variable. It is a StringIO instance.
 RSpec.configure do |config|
   include RSpec::LoggingHelper
+  config.include FakeFS::SpecHelpers, fakefs: true
   config.include JsonSpec::Helpers
   config.include WebMock::API
   config.capture_log_messages