diff --git a/include/nlohmann/json.hpp b/include/nlohmann/json.hpp
index 2e116f104b..ae5c0a5522 100644
--- a/include/nlohmann/json.hpp
+++ b/include/nlohmann/json.hpp
@@ -3692,10 +3692,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 #endif
     }
 
+    // template<typename ScalarType, typename std::enable_if<
+    //              std::is_scalar<ScalarType>::value, int>::type = 0>
     /// @brief comparison: equal
     /// @sa https://json.nlohmann.me/api/basic_json/operator_eq/
-    template <typename T>
-    requires detail::json_compatible_type<T, basic_json_t>::value
+    template <typename T,
+              std::enable_if<detail::json_compatible_type<T, basic_json_t>::value, int>::type = 0>
     bool operator==(T rhs) const noexcept
     {
         return *this == basic_json(rhs);
diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index 8ef520dc0c..44c7f5f3ff 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -22912,10 +22912,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 #endif
     }
 
+    // template<typename ScalarType, typename std::enable_if<
+    //              std::is_scalar<ScalarType>::value, int>::type = 0>
     /// @brief comparison: equal
     /// @sa https://json.nlohmann.me/api/basic_json/operator_eq/
-    template <typename T>
-    requires detail::json_compatible_type<T, basic_json_t>::value
+    template <typename T,
+              std::enable_if<detail::json_compatible_type<T, basic_json_t>::value, int>::type = 0>
     bool operator==(T rhs) const noexcept
     {
         return *this == basic_json(rhs);