diff --git a/.fixtures.yml b/.fixtures.yml
index f7f1eba..dc6b41f 100644
--- a/.fixtures.yml
+++ b/.fixtures.yml
@@ -2,6 +2,6 @@ fixtures:
   repositories:
     'stdlib':
       repo: 'git://github.com/puppetlabs/puppetlabs-stdlib.git'
-      ref: '3.0.0'
+      ref: '4.0.0'
   symlinks:
     'concat': '#{source_dir}'
diff --git a/Modulefile b/Modulefile
index 2e9b6b9..c90d6f4 100644
--- a/Modulefile
+++ b/Modulefile
@@ -6,4 +6,4 @@ license 'Apache 2.0'
 summary 'Concat module'
 description 'Concat module'
 project_page 'http://github.com/puppetlabs/puppetlabs-concat'
-dependency 'puppetlabs/stdlib', '>= 3.0.0'
+dependency 'puppetlabs/stdlib', '>= 4.0.0'