diff --git a/include/utilities/dsl/n_ary_op.hpp b/include/utilities/dsl/n_ary_op.hpp
index 6abf7a0b..0980ea56 100644
--- a/include/utilities/dsl/n_ary_op.hpp
+++ b/include/utilities/dsl/n_ary_op.hpp
@@ -71,7 +71,7 @@ class NAryOp : public Term<DerivedType> {
      *             throws. Same throw guarantee.
      */
     template<typename... Args2>
-    NAryOp(Args2&&... args) :
+    explicit NAryOp(Args2&&... args) :
       m_objects_(TermTraits<std::decay_t<Args2>>::make_holder(
         std::forward<Args2>(args))...) {}