diff --git a/fmt/format.h b/fmt/format.h
index 5fb9611b..da1ef297 100644
--- a/fmt/format.h
+++ b/fmt/format.h
@@ -165,24 +165,11 @@
 # endif
 #endif
 
-// A macro to disallow the copy constructor and operator= functions
-// This should be used in the private: declarations for a class
-#ifndef FMT_USE_DELETED_FUNCTIONS
-# define FMT_USE_DELETED_FUNCTIONS 0
-#endif
-
-#if FMT_USE_DELETED_FUNCTIONS || FMT_HAS_FEATURE(cxx_deleted_functions) || \
-  FMT_GCC_VERSION >= 404 || FMT_MSC_VER >= 1800
-# define FMT_DELETED_OR_UNDEFINED = delete
-# define FMT_DISALLOW_COPY_AND_ASSIGN(TypeName) \
+// A macro to disallow the copy construction and assignment.
+#define FMT_DISALLOW_COPY_AND_ASSIGN(TypeName) \
     TypeName(const TypeName&) = delete; \
     TypeName& operator=(const TypeName&) = delete
-#else
-# define FMT_DELETED_OR_UNDEFINED
-# define FMT_DISALLOW_COPY_AND_ASSIGN(TypeName) \
-    TypeName(const TypeName&); \
-    TypeName& operator=(const TypeName&)
-#endif
+#define FMT_DELETED_OR_UNDEFINED = delete
 
 #ifndef FMT_USE_USER_DEFINED_LITERALS
 // All compilers which support UDLs also support variadic templates. This
@@ -1447,27 +1434,12 @@ basic_arg<Context> make_arg(const T &value) {
   return arg;
 }
 
-#define FMT_CONCAT(a, b) a##b
-
 #if FMT_GCC_VERSION >= 407
 # define FMT_UNUSED __attribute__((unused))
 #else
 # define FMT_UNUSED
 #endif
 
-#ifndef FMT_USE_STATIC_ASSERT
-# define FMT_USE_STATIC_ASSERT 0
-#endif
-
-#if FMT_USE_STATIC_ASSERT || FMT_HAS_FEATURE(cxx_static_assert) || \
-  FMT_GCC_VERSION >= 403 || _MSC_VER >= 1600
-# define FMT_STATIC_ASSERT(cond, message) static_assert(cond, message)
-#else
-# define FMT_CONCAT_(a, b) FMT_CONCAT(a, b)
-# define FMT_STATIC_ASSERT(cond, message) \
-  typedef int FMT_CONCAT_(Assert, __LINE__)[(cond) ? 1 : -1] FMT_UNUSED
-#endif
-
 template <typename Context>
 struct named_arg : basic_arg<Context> {
   typedef typename Context::char_type Char;
diff --git a/fmt/posix.cc b/fmt/posix.cc
index 59e92539..1d473d22 100644
--- a/fmt/posix.cc
+++ b/fmt/posix.cc
@@ -144,7 +144,7 @@ long long fmt::File::size() const {
   Stat file_stat = Stat();
   if (FMT_POSIX_CALL(fstat(fd_, &file_stat)) == -1)
     throw system_error(errno, "cannot get file attributes");
-  FMT_STATIC_ASSERT(sizeof(long long) >= sizeof(file_stat.st_size),
+  static_assert(sizeof(long long) >= sizeof(file_stat.st_size),
       "return type of File::size is not large enough");
   return file_stat.st_size;
 #endif
diff --git a/test/posix-mock-test.cc b/test/posix-mock-test.cc
index ece17e8d..c132e1e7 100644
--- a/test/posix-mock-test.cc
+++ b/test/posix-mock-test.cc
@@ -218,12 +218,6 @@ void write_file(fmt::cstring_view filename, fmt::string_view content) {
   f.print("{}", content);
 }
 
-TEST(UtilTest, StaticAssert) {
-  FMT_STATIC_ASSERT(true, "success");
-  // Static assertion failure is tested in compile-test because it causes
-  // a compile-time error.
-}
-
 TEST(UtilTest, GetPageSize) {
 #ifdef _WIN32
   SYSTEM_INFO si = {};