diff --git a/include/boost/leaf/pred.hpp b/include/boost/leaf/pred.hpp
index 136368a7..480b0f50 100644
--- a/include/boost/leaf/pred.hpp
+++ b/include/boost/leaf/pred.hpp
@@ -65,7 +65,7 @@ struct condition<Enum, Enum>
 
 #if __cplusplus >= 201703L
 template <class ErrorCodeEnum>
-BOOST_LEAF_CONSTEXPR inline bool category( std::error_code const & ec )
+BOOST_LEAF_CONSTEXPR bool category( std::error_code const & ec )
 {
     static_assert(std::is_error_code_enum<ErrorCodeEnum>::value, "leaf::category requires an error code enum");
     return &ec.category() == &std::error_code(ErrorCodeEnum{}).category();