diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9f95fb58..a4a02096 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -26,6 +26,7 @@ endif()
 # Compiler config
 # ---------------------------------------------------------------------------------------
 set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 # make sure __cplusplus is defined when using msvc and enable parallel build
 if(MSVC)
@@ -115,7 +116,6 @@ endif()
 
 option(SPDLOG_PREVENT_CHILD_FD "Prevent from child processes to inherit log file descriptors" OFF)
 option(SPDLOG_NO_THREAD_ID "prevent spdlog from querying the thread id on each log call if thread id is not needed" OFF)
-option(SPDLOG_NO_TLS "prevent spdlog from using thread local storage" OFF)
 option(
     SPDLOG_NO_ATOMIC_LEVELS
     "prevent spdlog from using of std::atomic log levels (use only if your code never modifies log levels concurrently"
@@ -237,7 +237,6 @@ foreach(
     SPDLOG_CLOCK_COARSE
     SPDLOG_PREVENT_CHILD_FD
     SPDLOG_NO_THREAD_ID
-    SPDLOG_NO_TLS
     SPDLOG_NO_ATOMIC_LEVELS
     SPDLOG_DISABLE_DEFAULT_LOGGER
     SPDLOG_USE_STD_FORMAT)
diff --git a/include/spdlog/common.h b/include/spdlog/common.h
index 7df7e3cd..e3c97772 100644
--- a/include/spdlog/common.h
+++ b/include/spdlog/common.h
@@ -58,13 +58,6 @@
 #endif
 
 
-// disable thread local on msvc 2013
-#ifndef SPDLOG_NO_TLS
-#    if (defined(_MSC_VER) && (_MSC_VER < 1900)) || defined(__cplusplus_winrt)
-#        define SPDLOG_NO_TLS 1
-#    endif
-#endif
-
 #ifndef SPDLOG_FUNCTION
 #    define SPDLOG_FUNCTION static_cast<const char *>(__FUNCTION__)
 #endif
@@ -138,11 +131,7 @@ template<class T>
 using remove_cvref_t = typename std::remove_cv<typename std::remove_reference<T>::type>::type;
 
 template<typename Char>
-#    if FMT_VERSION >= 90101
 using fmt_runtime_string = fmt::runtime_format_string<Char>;
-#    else
-using fmt_runtime_string = fmt::basic_runtime<Char>;
-#    endif
 
 // clang doesn't like SFINAE disabled constructor in std::is_convertible<> so have to repeat the condition from basic_format_string here,
 // in addition, fmt::basic_runtime<Char> is only convertible to basic_format_string<Char> but not basic_string_view<Char>
diff --git a/include/spdlog/details/os-inl.h b/include/spdlog/details/os-inl.h
index b6aaac43..12b59f72 100644
--- a/include/spdlog/details/os-inl.h
+++ b/include/spdlog/details/os-inl.h
@@ -385,12 +385,9 @@ SPDLOG_INLINE size_t _thread_id() noexcept
 // Return current thread id as size_t (from thread local storage)
 SPDLOG_INLINE size_t thread_id() noexcept
 {
-#if defined(SPDLOG_NO_TLS)
-    return _thread_id();
-#else // cache thread id in tls
+    // cache thread id in tls
     static thread_local const size_t tid = _thread_id();
     return tid;
-#endif
 }
 
 // This is avoid msvc issue in sleep_for that happens if the clock changes.
diff --git a/include/spdlog/tweakme.h b/include/spdlog/tweakme.h
index b3ef0d68..8b11176f 100644
--- a/include/spdlog/tweakme.h
+++ b/include/spdlog/tweakme.h
@@ -36,15 +36,6 @@
 // #define SPDLOG_NO_THREAD_ID
 ///////////////////////////////////////////////////////////////////////////////
 
-///////////////////////////////////////////////////////////////////////////////
-// Uncomment to prevent spdlog from using thread local storage.
-//
-// WARNING: if your program forks, UNCOMMENT this flag to prevent undefined
-// thread ids in the children logs.
-//
-// #define SPDLOG_NO_TLS
-///////////////////////////////////////////////////////////////////////////////
-
 ///////////////////////////////////////////////////////////////////////////////
 // Uncomment to avoid spdlog's usage of atomic log levels
 // Use only if your code never modifies a logger's log levels concurrently by