diff --git a/include/boost/mp11/detail/mp_count.hpp b/include/boost/mp11/detail/mp_count.hpp
index c03128f..12bde18 100644
--- a/include/boost/mp11/detail/mp_count.hpp
+++ b/include/boost/mp11/detail/mp_count.hpp
@@ -36,6 +36,12 @@ template<class T1, class... T> constexpr std::size_t cx_plus(T1 t1, T... t)
     return t1 + cx_plus(t...);
 }
 
+template<class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10, class... T>
+constexpr std::size_t cx_plus(T1 t1, T2 t2, T3 t3, T4 t4, T5 t5, T6 t6, T7 t7, T8 t8, T9 t9, T10 t10, T... t)
+{
+    return t1 + t2 + t3 + t4 + t5 + t6 + t7 + t8 + t9 + t10 + cx_plus(t...);
+}
+
 template<template<class...> class L, class... T, class V> struct mp_count_impl<L<T...>, V>
 {
     using type = mp_size_t<cx_plus(std::is_same<T, V>::value...)>;