diff --git a/include/boost/math/quaternion.hpp b/include/boost/math/quaternion.hpp index 94e667108..bbccce1b6 100644 --- a/include/boost/math/quaternion.hpp +++ b/include/boost/math/quaternion.hpp @@ -16,6 +16,7 @@ #include // for the "<<" operator #include // for BOOST_NO_STD_LOCALE +#include #ifndef BOOST_NO_STD_LOCALE #include // for the "<<" operator #endif /* BOOST_NO_STD_LOCALE */