diff --git a/Puppetfile b/Puppetfile
index ffbeaad1c..e5d811dec 100644
--- a/Puppetfile
+++ b/Puppetfile
@@ -180,7 +180,7 @@ mod 'apt',
 
 mod 'concat',
   :git => 'https://github.com/puppetlabs/puppetlabs-concat',
-  :ref => '4.0.0'
+  :ref => '3.0.0'
 
 mod 'firewall',
   :git => 'https://github.com/puppetlabs/puppetlabs-firewall',
diff --git a/external_modules.txt b/external_modules.txt
index 125702a46..872e736ad 100644
--- a/external_modules.txt
+++ b/external_modules.txt
@@ -5,7 +5,7 @@ joshuabaird/puppet-ipaclient
 nanliu/puppet-staging
 puppetlabs/puppetlabs-apache
 puppetlabs/puppetlabs-apt
-puppetlabs/puppetlabs-concat
+puppetlabs/puppetlabs-concat,3.0.0
 puppetlabs/puppetlabs-firewall
 puppetlabs/puppetlabs-inifile
 puppetlabs/puppetlabs-mongodb