diff --git a/src/tupleref.hpp b/src/tupleref.hpp
index 3e896be..18bd7f4 100644
--- a/src/tupleref.hpp
+++ b/src/tupleref.hpp
@@ -17,7 +17,8 @@
 namespace detail
 {
 /** @brief Less than implementation for tuples of references. */
-template <size_t size, size_t i, typename T, typename U> struct TupleOfRefsLess
+template <size_t size, size_t i, typename T, typename U>
+struct TupleOfRefsLess
 {
     static constexpr bool compare(const T& l, const U& r)
     {