2 files changed, 16 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/connection_specification.rb b/activerecord/lib/active_record/connection_adapters/connection_specification.rb
index 34bdcc0802..8491d42b86 100644
--- a/activerecord/lib/active_record/connection_adapters/connection_specification.rb
+++ b/activerecord/lib/active_record/connection_adapters/connection_specification.rb
@@ -7,6 +7,10 @@ module ActiveRecord
         @config, @adapter_method = config, adapter_method
       end
 
+      def initialize_dup(original)
+        @config = original.config.dup
+      end
+
       ##
       # Builds a ConnectionSpecification from user input
       class Resolver # :nodoc:
diff --git a/activerecord/test/cases/connection_adapters/connection_specification_test.rb b/activerecord/test/cases/connection_adapters/connection_specification_test.rb
new file mode 100644
index 0000000000..ea2196cda2
--- /dev/null
+++ b/activerecord/test/cases/connection_adapters/connection_specification_test.rb
@@ -0,0 +1,12 @@
+require "cases/helper"
+
+module ActiveRecord
+  module ConnectionAdapters
+    class ConnectionSpecificationTest < ActiveRecord::TestCase
+      def test_dup_deep_copy_config
+        spec = ConnectionSpecification.new({ :a => :b }, "bar")
+        assert_not_equal(spec.config.object_id, spec.dup.config.object_id)
+      end
+    end
+  end
+end