diff --git a/include/nlohmann/detail/macro_scope.hpp b/include/nlohmann/detail/macro_scope.hpp
index cf94997e0..9117c7df9 100644
--- a/include/nlohmann/detail/macro_scope.hpp
+++ b/include/nlohmann/detail/macro_scope.hpp
@@ -32,8 +32,14 @@
 
 // C++ language standard detection
 // if the user manually specified the used C++ version, this is skipped
-#if !defined(JSON_HAS_CPP_23) && !defined(JSON_HAS_CPP_20) && !defined(JSON_HAS_CPP_17) && !defined(JSON_HAS_CPP_14) && !defined(JSON_HAS_CPP_11)
-    #if (defined(__cplusplus) && __cplusplus > 202002L) || (defined(_MSVC_LANG) && _MSVC_LANG > 202002L)
+#if !defined(JSON_HAS_CPP_26) && !defined(JSON_HAS_CPP_23) && !defined(JSON_HAS_CPP_20) && !defined(JSON_HAS_CPP_17) && !defined(JSON_HAS_CPP_14) && !defined(JSON_HAS_CPP_11)
+    #if (defined(__cplusplus) && __cplusplus > 202302L) || (defined(_MSVC_LANG) && _MSVC_LANG > 202302L)
+        #define JSON_HAS_CPP_26
+        #define JSON_HAS_CPP_23
+        #define JSON_HAS_CPP_20
+        #define JSON_HAS_CPP_17
+        #define JSON_HAS_CPP_14
+    #elif (defined(__cplusplus) && __cplusplus > 202002L) || (defined(_MSVC_LANG) && _MSVC_LANG > 202002L)
         #define JSON_HAS_CPP_23
         #define JSON_HAS_CPP_20
         #define JSON_HAS_CPP_17
diff --git a/include/nlohmann/detail/macro_unscope.hpp b/include/nlohmann/detail/macro_unscope.hpp
index 2edb1686d..236e89cac 100644
--- a/include/nlohmann/detail/macro_unscope.hpp
+++ b/include/nlohmann/detail/macro_unscope.hpp
@@ -35,6 +35,7 @@
     #undef JSON_HAS_CPP_17
     #undef JSON_HAS_CPP_20
     #undef JSON_HAS_CPP_23
+    #undef JSON_HAS_CPP_26
     #undef JSON_HAS_FILESYSTEM
     #undef JSON_HAS_EXPERIMENTAL_FILESYSTEM
     #undef JSON_HAS_THREE_WAY_COMPARISON
diff --git a/include/nlohmann/detail/output/binary_writer.hpp b/include/nlohmann/detail/output/binary_writer.hpp
index f1d533947..8fb2100b5 100644
--- a/include/nlohmann/detail/output/binary_writer.hpp
+++ b/include/nlohmann/detail/output/binary_writer.hpp
@@ -1813,8 +1813,21 @@ class binary_writer
                enable_if_t < std::is_signed<C>::value && std::is_unsigned<char>::value > * = nullptr >
     static CharType to_char_type(std::uint8_t x) noexcept
     {
-        static_assert(sizeof(std::uint8_t) == sizeof(CharType), "size of CharType must be equal to std::uint8_t");
+        // The std::is_trivial trait is deprecated in C++26. The replacement is to use
+        // std::is_trivially_copyable and std::is_trivially_default_constructible.
+        // However, some older library implementations support std::is_trivial
+        // but not all the std::is_trivially_* traits.
+        // Since detecting full support across all libraries is difficult,
+        // we use std::is_trivial unless we are using a standard where it has been deprecated.
+        // For more details, see: https://github.com/nlohmann/json/pull/4775#issuecomment-2884361627
+#ifdef JSON_HAS_CPP_26
+        static_assert(std::is_trivially_copyable<CharType>::value, "CharType must be trivially copyable");
+        static_assert(std::is_trivially_default_constructible<CharType>::value, "CharType must be trivially default constructible");
+#else
         static_assert(std::is_trivial<CharType>::value, "CharType must be trivial");
+#endif
+
+        static_assert(sizeof(std::uint8_t) == sizeof(CharType), "size of CharType must be equal to std::uint8_t");
         CharType result;
         std::memcpy(&result, &x, sizeof(x));
         return result;
diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index 31590ff65..ba55fd4fb 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -2395,8 +2395,14 @@ JSON_HEDLEY_DIAGNOSTIC_POP
 
 // C++ language standard detection
 // if the user manually specified the used C++ version, this is skipped
-#if !defined(JSON_HAS_CPP_23) && !defined(JSON_HAS_CPP_20) && !defined(JSON_HAS_CPP_17) && !defined(JSON_HAS_CPP_14) && !defined(JSON_HAS_CPP_11)
-    #if (defined(__cplusplus) && __cplusplus > 202002L) || (defined(_MSVC_LANG) && _MSVC_LANG > 202002L)
+#if !defined(JSON_HAS_CPP_26) && !defined(JSON_HAS_CPP_23) && !defined(JSON_HAS_CPP_20) && !defined(JSON_HAS_CPP_17) && !defined(JSON_HAS_CPP_14) && !defined(JSON_HAS_CPP_11)
+    #if (defined(__cplusplus) && __cplusplus > 202302L) || (defined(_MSVC_LANG) && _MSVC_LANG > 202302L)
+        #define JSON_HAS_CPP_26
+        #define JSON_HAS_CPP_23
+        #define JSON_HAS_CPP_20
+        #define JSON_HAS_CPP_17
+        #define JSON_HAS_CPP_14
+    #elif (defined(__cplusplus) && __cplusplus > 202002L) || (defined(_MSVC_LANG) && _MSVC_LANG > 202002L)
         #define JSON_HAS_CPP_23
         #define JSON_HAS_CPP_20
         #define JSON_HAS_CPP_17
@@ -17605,8 +17611,21 @@ class binary_writer
                enable_if_t < std::is_signed<C>::value && std::is_unsigned<char>::value > * = nullptr >
     static CharType to_char_type(std::uint8_t x) noexcept
     {
-        static_assert(sizeof(std::uint8_t) == sizeof(CharType), "size of CharType must be equal to std::uint8_t");
+        // The std::is_trivial trait is deprecated in C++26. The replacement is to use
+        // std::is_trivially_copyable and std::is_trivially_default_constructible.
+        // However, some older library implementations support std::is_trivial
+        // but not all the std::is_trivially_* traits.
+        // Since detecting full support across all libraries is difficult,
+        // we use std::is_trivial unless we are using a standard where it has been deprecated.
+        // For more details, see: https://github.com/nlohmann/json/pull/4775#issuecomment-2884361627
+#ifdef JSON_HAS_CPP_26
+        static_assert(std::is_trivially_copyable<CharType>::value, "CharType must be trivially copyable");
+        static_assert(std::is_trivially_default_constructible<CharType>::value, "CharType must be trivially default constructible");
+#else
         static_assert(std::is_trivial<CharType>::value, "CharType must be trivial");
+#endif
+
+        static_assert(sizeof(std::uint8_t) == sizeof(CharType), "size of CharType must be equal to std::uint8_t");
         CharType result;
         std::memcpy(&result, &x, sizeof(x));
         return result;
@@ -25407,6 +25426,7 @@ inline void swap(nlohmann::NLOHMANN_BASIC_JSON_TPL& j1, nlohmann::NLOHMANN_BASIC
     #undef JSON_HAS_CPP_17
     #undef JSON_HAS_CPP_20
     #undef JSON_HAS_CPP_23
+    #undef JSON_HAS_CPP_26
     #undef JSON_HAS_FILESYSTEM
     #undef JSON_HAS_EXPERIMENTAL_FILESYSTEM
     #undef JSON_HAS_THREE_WAY_COMPARISON