diff --git a/include/nlohmann/detail/meta/type_traits.hpp b/include/nlohmann/detail/meta/type_traits.hpp
index 8747a85e35..f017febf1b 100644
--- a/include/nlohmann/detail/meta/type_traits.hpp
+++ b/include/nlohmann/detail/meta/type_traits.hpp
@@ -684,10 +684,11 @@ inline constexpr bool value_in_range_of(T val)
 template<bool Value>
 using bool_constant = std::integral_constant<bool, Value>;
 
+
 template <typename T, typename BasicJsonType, typename U = uncvref_t<T>>
 struct json_compatible_type
 {
-    static constexpr auto value = !is_basic_json<U>::value && is_compatible_type<BasicJsonType, U>::value;
+    static constexpr bool value = !is_basic_json<U>::value && is_compatible_type<BasicJsonType, U>::value;
 };
 
 ///////////////////////////////////////////////////////////////////////////////