diff --git a/plugins/community_hub/Gemfile b/plugins/community_hub/Gemfile
index 4356f44..9edd33a 100644
--- a/plugins/community_hub/Gemfile
+++ b/plugins/community_hub/Gemfile
@@ -1,2 +1,3 @@
+source 'https://rubygems.org'
 gem 'twitter', '~> 5.8.0'
 gem 'proxifier', '~> 1.0.3'
diff --git a/plugins/oauth_client/Gemfile b/plugins/oauth_client/Gemfile
index f12771b..2aba102 100644
--- a/plugins/oauth_client/Gemfile
+++ b/plugins/oauth_client/Gemfile
@@ -1,3 +1,4 @@
+source 'https://rubygems.org'
 gem 'omniauth', '~> 1.2.2'
 gem 'omniauth-facebook', '~> 2.0.0'
 gem "omniauth-google-oauth2", '~> 0.2.6'
diff --git a/plugins/oauth_provider/Gemfile b/plugins/oauth_provider/Gemfile
index ccaff8e..e2e947e 100644
--- a/plugins/oauth_provider/Gemfile
+++ b/plugins/oauth_provider/Gemfile
@@ -1 +1,2 @@
+source 'https://rubygems.org'
 gem 'doorkeeper', '~> 1.4.0'
diff --git a/plugins/serpro_integration/Gemfile b/plugins/serpro_integration/Gemfile
index d07ee15..506fbd6 100644
--- a/plugins/serpro_integration/Gemfile
+++ b/plugins/serpro_integration/Gemfile
@@ -1,2 +1,3 @@
+source 'https://rubygems.org'
 gem 'gitlab', '~> 3.3.0'
 gem 'jenkins_api_client', '~> 0.14.1'
diff --git a/plugins/virtuoso/Gemfile b/plugins/virtuoso/Gemfile
index ef702ae..b1b9d93 100644
--- a/plugins/virtuoso/Gemfile
+++ b/plugins/virtuoso/Gemfile
@@ -1,3 +1,4 @@
+source 'https://rubygems.org'
 gem 'rdf'
 gem 'rdf-virtuoso'
 gem 'oai'
--
libgit2 0.21.2