diff --git a/include/nlohmann/detail/meta/cpp_future.hpp b/include/nlohmann/detail/meta/cpp_future.hpp
index 147f2fa35..ef2da370d 100644
--- a/include/nlohmann/detail/meta/cpp_future.hpp
+++ b/include/nlohmann/detail/meta/cpp_future.hpp
@@ -147,8 +147,12 @@ struct static_const
     static constexpr T value{};
 };
 
-template<typename T>
-constexpr T static_const<T>::value; // NOLINT(readability-redundant-declaration)
+#ifndef JSON_HAS_CPP_17
+
+    template<typename T>
+    constexpr T static_const<T>::value; // NOLINT(readability-redundant-declaration)
+
+#endif
 
 }  // namespace detail
 }  // namespace nlohmann
diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index 09945b5b7..71f6814ad 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -3191,8 +3191,12 @@ struct static_const
     static constexpr T value{};
 };
 
-template<typename T>
-constexpr T static_const<T>::value; // NOLINT(readability-redundant-declaration)
+#ifndef JSON_HAS_CPP_17
+
+    template<typename T>
+    constexpr T static_const<T>::value; // NOLINT(readability-redundant-declaration)
+
+#endif
 
 }  // namespace detail
 }  // namespace nlohmann