diff --git a/.travis.yml b/.travis.yml
index c8a882f..037983e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -12,7 +12,7 @@ rvm:
   - 2.4.5
   - 2.5.3
   - 2.6.1
-  - jruby-9.2.4.1
+  - jruby-9.2.5.0
 env:
   global:
     - JRUBY_OPTS='--dev -J-Xmx1024M'
diff --git a/lib/dry/container/namespace_dsl.rb b/lib/dry/container/namespace_dsl.rb
index 9812a9f..b9b4300 100644
--- a/lib/dry/container/namespace_dsl.rb
+++ b/lib/dry/container/namespace_dsl.rb
@@ -1,3 +1,5 @@
+require 'delegate'
+
 module Dry
   class Container
     # @api private