diff --git a/spec/support/coverage.rb b/spec/support/coverage.rb
new file mode 100644
index 0000000..ca445f9
--- /dev/null
+++ b/spec/support/coverage.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+# this file is managed by dry-rb/devtools
+
+if ENV["COVERAGE"] == "true"
+  require "simplecov"
+  require "simplecov-cobertura"
+
+  SimpleCov.formatter = SimpleCov::Formatter::CoberturaFormatter
+
+  SimpleCov.start do
+    add_filter "/spec/"
+    enable_coverage :branch
+  end
+end