diff --git a/dev-ruby/dry-monads/dry-monads-1.6.0.ebuild b/dev-ruby/dry-monads/dry-monads-1.6.0.ebuild
index 0ed9ef832c27f..c9bedd157b163 100644
--- a/dev-ruby/dry-monads/dry-monads-1.6.0.ebuild
+++ b/dev-ruby/dry-monads/dry-monads-1.6.0.ebuild
@@ -31,4 +31,5 @@ ruby_add_rdepend "
 
 ruby_add_bdepend "test? (
 	dev-ruby/dry-types
+	dev-ruby/warning
 )"