diff --git a/Grid/json/json.hpp b/Grid/json/json.hpp
index cb27e0581..eb715ef42 100644
--- a/Grid/json/json.hpp
+++ b/Grid/json/json.hpp
@@ -21895,7 +21895,7 @@ inline void swap(nlohmann::NLOHMANN_BASIC_JSON_TPL& j1, nlohmann::NLOHMANN_BASIC
 /// @brief user-defined string literal for JSON values
 /// @sa https://json.nlohmann.me/api/basic_json/operator_literal_json/
 JSON_HEDLEY_NON_NULL(1)
-inline nlohmann::json operator "" _json(const char* s, std::size_t n)
+inline nlohmann::json operator ""_json(const char* s, std::size_t n)
 {
     return nlohmann::json::parse(s, s + n);
 }
@@ -21903,7 +21903,7 @@ inline nlohmann::json operator "" _json(const char* s, std::size_t n)
 /// @brief user-defined string literal for JSON pointer
 /// @sa https://json.nlohmann.me/api/basic_json/operator_literal_json_pointer/
 JSON_HEDLEY_NON_NULL(1)
-inline nlohmann::json::json_pointer operator "" _json_pointer(const char* s, std::size_t n)
+inline nlohmann::json::json_pointer operator ""_json_pointer(const char* s, std::size_t n)
 {
     return nlohmann::json::json_pointer(std::string(s, n));
 }