diff --git a/include/fmt/color.h b/include/fmt/color.h
index 68c0f16a..df912fe2 100644
--- a/include/fmt/color.h
+++ b/include/fmt/color.h
@@ -189,7 +189,7 @@ enum class color : uint32_t {
   white                   = 0xFFFFFF, // rgb(255,255,255)
   white_smoke             = 0xF5F5F5, // rgb(245,245,245)
   yellow                  = 0xFFFF00, // rgb(255,255,0)
-  yellow_green            = 0x9ACD32, // rgb(154,205,50)
+  yellow_green            = 0x9ACD32  // rgb(154,205,50)
 };  // enum class color
 
 // rgb is a struct for red, green and blue colors.
diff --git a/include/fmt/core.h b/include/fmt/core.h
index 3c522403..f24d5c5f 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -91,8 +91,10 @@
 
 #if FMT_HAS_FEATURE(cxx_explicit_conversions) || \
     FMT_GCC_VERSION >= 405 || FMT_MSC_VER >= 1800
+# define FMT_USE_EXPLICIT 1
 # define FMT_EXPLICIT explicit
 #else
+# define FMT_USE_EXPLICIT 0
 # define FMT_EXPLICIT
 #endif
 
@@ -658,7 +660,12 @@ FMT_MAKE_VALUE_SAME(long_long_type, long long)
 FMT_MAKE_VALUE_SAME(ulong_long_type, unsigned long long)
 FMT_MAKE_VALUE(int_type, signed char, int)
 FMT_MAKE_VALUE(uint_type, unsigned char, unsigned)
-FMT_MAKE_VALUE(char_type, typename C::char_type, int)
+
+// This doesn't use FMT_MAKE_VALUE because of ambiguity in gcc 4.4.
+template <typename C, typename Char>
+FMT_CONSTEXPR typename std::enable_if<
+  std::is_same<typename C::char_type, Char>::value,
+  init<C, int, char_type>>::type make_value(Char val) { return val; }
 
 template <typename C>
 FMT_CONSTEXPR typename std::enable_if<
@@ -718,7 +725,7 @@ inline typename std::enable_if<
 
 template <typename C, typename T, typename Char = typename C::char_type>
 inline typename std::enable_if<
-    !convert_to_int<T, Char>::value &&
+    !convert_to_int<T, Char>::value && !std::is_same<T, Char>::value &&
     !std::is_convertible<T, basic_string_view<Char>>::value &&
     !internal::is_constructible<basic_string_view<Char>, T>::value &&
     !internal::has_to_string_view<T>::value,
diff --git a/include/fmt/format.h b/include/fmt/format.h
index 428e4a29..0d925440 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -1725,7 +1725,7 @@ FMT_CONSTEXPR void set_dynamic_spec(
     T &value, basic_format_arg<Context> arg, ErrorHandler eh) {
   unsigned long long big_value =
       visit_format_arg(Handler<ErrorHandler>(eh), arg);
-  if (big_value > (std::numeric_limits<int>::max)())
+  if (big_value > to_unsigned((std::numeric_limits<int>::max)()))
     eh.on_error("number is too big");
   value = static_cast<T>(big_value);
 }
@@ -2111,7 +2111,7 @@ FMT_CONSTEXPR void parse_format_string(
     ++p;
     if (p == end)
       return handler.on_error("invalid format string");
-    if (*p == '}') {
+    if (static_cast<char>(*p) == '}') {
       handler.on_arg_id();
       handler.on_replacement_field(p);
     } else if (*p == '{') {
diff --git a/test/core-test.cc b/test/core-test.cc
index 245c1768..77d35428 100644
--- a/test/core-test.cc
+++ b/test/core-test.cc
@@ -65,6 +65,7 @@ struct formatter<test_struct, Char> {
 };
 FMT_END_NAMESPACE
 
+#if !FMT_GCC_VERSION || FMT_GCC_VERSION >= 470
 TEST(BufferTest, Noncopyable) {
   EXPECT_FALSE(std::is_copy_constructible<basic_buffer<char> >::value);
 #if !FMT_MSC_VER
@@ -80,11 +81,12 @@ TEST(BufferTest, Nonmoveable) {
   EXPECT_FALSE(std::is_move_assignable<basic_buffer<char> >::value);
 #endif
 }
+#endif
 
 // A test buffer with a dummy grow method.
 template <typename T>
 struct test_buffer : basic_buffer<T> {
-  void grow(std::size_t capacity) { this->set(nullptr, capacity); }
+  void grow(std::size_t capacity) { this->set(FMT_NULL, capacity); }
 };
 
 template <typename T>
@@ -104,7 +106,7 @@ struct mock_buffer : basic_buffer<T> {
 TEST(BufferTest, Ctor) {
   {
     mock_buffer<int> buffer;
-    EXPECT_EQ(nullptr, &buffer[0]);
+    EXPECT_EQ(FMT_NULL, &buffer[0]);
     EXPECT_EQ(static_cast<size_t>(0), buffer.size());
     EXPECT_EQ(static_cast<size_t>(0), buffer.capacity());
   }
@@ -219,7 +221,7 @@ struct custom_context {
 
       const char *format(const T &, custom_context& ctx) {
         ctx.called = true;
-        return nullptr;
+        return FMT_NULL;
       }
     };
   };
@@ -365,8 +367,8 @@ TEST(ArgTest, WStringArg) {
 }
 
 TEST(ArgTest, PointerArg) {
-  void *p = nullptr;
-  const void *cp = nullptr;
+  void *p = FMT_NULL;
+  const void *cp = FMT_NULL;
   CHECK_ARG_(char, cp, p);
   CHECK_ARG_(wchar_t, cp, p);
   CHECK_ARG(cp, );
@@ -377,7 +379,7 @@ struct check_custom {
       fmt::basic_format_arg<fmt::format_context>::handle h) const {
     struct test_buffer : fmt::internal::basic_buffer<char> {
       char data[10];
-      test_buffer() : basic_buffer(data, 0, 10) {}
+      test_buffer() : fmt::internal::basic_buffer<char>(data, 0, 10) {}
       void grow(std::size_t) {}
     } buffer;
     fmt::internal::basic_buffer<char> &base = buffer;
diff --git a/test/format-impl-test.cc b/test/format-impl-test.cc
index 63b6c405..1f584e06 100644
--- a/test/format-impl-test.cc
+++ b/test/format-impl-test.cc
@@ -136,9 +136,9 @@ TEST(FormatTest, FormatNegativeNaN) {
 }
 
 TEST(FormatTest, StrError) {
-  char *message = nullptr;
+  char *message = FMT_NULL;
   char buffer[BUFFER_SIZE];
-  EXPECT_ASSERT(fmt::safe_strerror(EDOM, message = nullptr, 0),
+  EXPECT_ASSERT(fmt::safe_strerror(EDOM, message = FMT_NULL, 0),
                 "invalid buffer");
   EXPECT_ASSERT(fmt::safe_strerror(EDOM, message = buffer, 0),
                 "invalid buffer");
diff --git a/test/format-test.cc b/test/format-test.cc
index 2f227bf0..a30da8e9 100644
--- a/test/format-test.cc
+++ b/test/format-test.cc
@@ -212,7 +212,7 @@ TEST(AllocatorTest, allocator_ref) {
   test_allocator_ref ref2(ref);
   check_forwarding(alloc, ref2);
   test_allocator_ref ref3;
-  EXPECT_EQ(nullptr, ref3.get());
+  EXPECT_EQ(FMT_NULL, ref3.get());
   ref3 = ref;
   check_forwarding(alloc, ref3);
 }
@@ -228,7 +228,7 @@ static void check_move_buffer(const char *str,
   EXPECT_EQ(str, std::string(&buffer2[0], buffer2.size()));
   EXPECT_EQ(5u, buffer2.capacity());
   // Move should transfer allocator.
-  EXPECT_EQ(nullptr, buffer.get_allocator().get());
+  EXPECT_EQ(FMT_NULL, buffer.get_allocator().get());
   EXPECT_EQ(alloc, buffer2.get_allocator().get());
 }
 
@@ -313,7 +313,7 @@ TEST(MemoryBufferTest, Grow) {
 TEST(MemoryBufferTest, Allocator) {
   typedef allocator_ref< mock_allocator<char> > TestAllocator;
   basic_memory_buffer<char, 10, TestAllocator> buffer;
-  EXPECT_EQ(nullptr, buffer.get_allocator().get());
+  EXPECT_EQ(FMT_NULL, buffer.get_allocator().get());
   StrictMock< mock_allocator<char> > alloc;
   char mem;
   {
@@ -453,7 +453,7 @@ TEST(UtilTest, FormatSystemError) {
     fmt::print("warning: std::allocator allocates {} chars", max_size);
     return;
   }
-  fmt::format_system_error(message, EDOM, fmt::string_view(nullptr, max_size));
+  fmt::format_system_error(message, EDOM, fmt::string_view(FMT_NULL, max_size));
   EXPECT_EQ(fmt::format("error {}", EDOM), to_string(message));
 }
 
@@ -1489,7 +1489,7 @@ TEST(FormatterTest, FormatCString) {
   EXPECT_EQ("test", format("{0:s}", "test"));
   char nonconst[] = "nonconst";
   EXPECT_EQ("nonconst", format("{0}", nonconst));
-  EXPECT_THROW_MSG(format("{0}", static_cast<const char*>(nullptr)),
+  EXPECT_THROW_MSG(format("{0}", static_cast<const char*>(FMT_NULL)),
       format_error, "string pointer is null");
 }
 
@@ -1511,7 +1511,7 @@ TEST(FormatterTest, FormatUCharString) {
 
 TEST(FormatterTest, FormatPointer) {
   check_unknown_types(reinterpret_cast<void*>(0x1234), "p", "pointer");
-  EXPECT_EQ("0x0", format("{0}", static_cast<void*>(nullptr)));
+  EXPECT_EQ("0x0", format("{0}", static_cast<void*>(FMT_NULL)));
   EXPECT_EQ("0x1234", format("{0}", reinterpret_cast<void*>(0x1234)));
   EXPECT_EQ("0x1234", format("{0:p}", reinterpret_cast<void*>(0x1234)));
   EXPECT_EQ("0x" + std::string(sizeof(void*) * CHAR_BIT / 4, 'f'),
@@ -1546,7 +1546,7 @@ TEST(FormatterTest, FormatImplicitlyConvertibleToStringView) {
 }
 
 // std::is_constructible is broken in MSVC until version 2015.
-#if !FMT_MSC_VER || FMT_MSC_VER >= 1900
+#if FMT_USE_EXPLICIT && (!FMT_MSC_VER || FMT_MSC_VER >= 1900)
 struct explicitly_convertible_to_string_view {
   explicit operator fmt::string_view() const { return "foo"; }
 };
@@ -1652,7 +1652,7 @@ TEST(FormatterTest, FormatExamples) {
   FILE *ftest = safe_fopen(filename, "r");
   if (ftest) fclose(ftest);
   int error_code = errno;
-  EXPECT_TRUE(ftest == nullptr);
+  EXPECT_TRUE(ftest == FMT_NULL);
   EXPECT_SYSTEM_ERROR({
     FILE *f = safe_fopen(filename, "r");
     if (!f)
@@ -1769,7 +1769,7 @@ TEST(FormatTest, Variadic) {
 }
 
 TEST(FormatTest, Dynamic) {
-  using ctx = fmt::format_context;
+  typedef fmt::format_context ctx;
   std::vector<fmt::basic_format_arg<ctx>> args;
   args.emplace_back(fmt::internal::make_arg<ctx>(42));
   args.emplace_back(fmt::internal::make_arg<ctx>("abc1"));
@@ -2321,7 +2321,7 @@ FMT_CONSTEXPR bool equal(const char *s1, const char *s2) {
 
 template <typename... Args>
 FMT_CONSTEXPR bool test_error(const char *fmt, const char *expected_error) {
-  const char *actual_error = nullptr;
+  const char *actual_error = FMT_NULL;
   fmt::internal::check_format_string<char, test_error_handler, Args...>(
         string_view(fmt, len(fmt)), test_error_handler(actual_error));
   return equal(actual_error, expected_error);
@@ -2333,7 +2333,7 @@ FMT_CONSTEXPR bool test_error(const char *fmt, const char *expected_error) {
   static_assert(test_error<__VA_ARGS__>(fmt, error), "")
 
 TEST(FormatTest, FormatStringErrors) {
-  EXPECT_ERROR_NOARGS("foo", nullptr);
+  EXPECT_ERROR_NOARGS("foo", FMT_NULL);
   EXPECT_ERROR_NOARGS("}", "unmatched '}' in format string");
   EXPECT_ERROR("{0:s", "unknown format specifier", Date);
 #ifndef _MSC_VER
diff --git a/test/gtest-extra-test.cc b/test/gtest-extra-test.cc
index 13596b18..97abf539 100644
--- a/test/gtest-extra-test.cc
+++ b/test/gtest-extra-test.cc
@@ -340,10 +340,10 @@ TEST(OutputRedirectTest, FlushErrorInCtor) {
   // Put a character in a file buffer.
   EXPECT_EQ('x', fputc('x', f.get()));
   FMT_POSIX(close(write_fd));
-  scoped_ptr<OutputRedirect> redir{nullptr};
+  scoped_ptr<OutputRedirect> redir{FMT_NULL};
   EXPECT_SYSTEM_ERROR_NOASSERT(redir.reset(new OutputRedirect(f.get())),
       EBADF, "cannot flush stream");
-  redir.reset(nullptr);
+  redir.reset(FMT_NULL);
   write_copy.dup2(write_fd);  // "undo" close or dtor will fail
 }
 
@@ -352,7 +352,7 @@ TEST(OutputRedirectTest, DupErrorInCtor) {
   int fd = (f.fileno)();
   file copy = file::dup(fd);
   FMT_POSIX(close(fd));
-  scoped_ptr<OutputRedirect> redir{nullptr};
+  scoped_ptr<OutputRedirect> redir{FMT_NULL};
   EXPECT_SYSTEM_ERROR_NOASSERT(redir.reset(new OutputRedirect(f.get())),
       EBADF, fmt::format("cannot duplicate file descriptor {}", fd));
   copy.dup2(fd);  // "undo" close or dtor will fail
@@ -403,7 +403,7 @@ TEST(OutputRedirectTest, ErrorInDtor) {
       // output in EXPECT_STDERR and the second close will break output
       // redirection.
       FMT_POSIX(close(write_fd));
-      SUPPRESS_ASSERT(redir.reset(nullptr));
+      SUPPRESS_ASSERT(redir.reset(FMT_NULL));
   }, format_system_error(EBADF, "cannot flush stream"));
   write_copy.dup2(write_fd); // "undo" close or dtor of buffered_file will fail
 }
diff --git a/test/gtest-extra.h b/test/gtest-extra.h
index c3728f53..61e262e4 100644
--- a/test/gtest-extra.h
+++ b/test/gtest-extra.h
@@ -155,7 +155,7 @@ std::string read(fmt::file &f, std::size_t count);
 template <typename Mock>
 struct ScopedMock : testing::StrictMock<Mock> {
   ScopedMock() { Mock::instance = this; }
-  ~ScopedMock() { Mock::instance = nullptr; }
+  ~ScopedMock() { Mock::instance = FMT_NULL; }
 };
 
 #endif  // FMT_GTEST_EXTRA_H_
diff --git a/test/mock-allocator.h b/test/mock-allocator.h
index 87769690..65ee6ab8 100644
--- a/test/mock-allocator.h
+++ b/test/mock-allocator.h
@@ -28,13 +28,13 @@ class allocator_ref {
 
   void move(allocator_ref &other) {
     alloc_ = other.alloc_;
-    other.alloc_ = nullptr;
+    other.alloc_ = FMT_NULL;
   }
 
  public:
   typedef typename Allocator::value_type value_type;
 
-  explicit allocator_ref(Allocator *alloc = nullptr) : alloc_(alloc) {}
+  explicit allocator_ref(Allocator *alloc = FMT_NULL) : alloc_(alloc) {}
 
   allocator_ref(const allocator_ref &other) : alloc_(other.alloc_) {}
   allocator_ref(allocator_ref &&other) { move(other); }
diff --git a/test/ostream-test.cc b/test/ostream-test.cc
index 50b8e4e8..76db8b3a 100644
--- a/test/ostream-test.cc
+++ b/test/ostream-test.cc
@@ -146,7 +146,7 @@ TEST(OStreamTest, WriteToOStreamMaxSize) {
   } os(streambuf);
 
   testing::InSequence sequence;
-  const char *data = nullptr;
+  const char *data = FMT_NULL;
   std::size_t size = max_size;
   do {
     typedef std::make_unsigned<std::streamsize>::type ustreamsize;
diff --git a/test/posix-mock-test.cc b/test/posix-mock-test.cc
index 83a9ac3c..8b0e14e1 100644
--- a/test/posix-mock-test.cc
+++ b/test/posix-mock-test.cc
@@ -133,7 +133,7 @@ int test::dup2(int fildes, int fildes2) {
 }
 
 FILE *test::fdopen(int fildes, const char *mode) {
-  EMULATE_EINTR(fdopen, nullptr);
+  EMULATE_EINTR(fdopen, FMT_NULL);
   return ::FMT_POSIX(fdopen(fildes, mode));
 }
 
@@ -162,7 +162,7 @@ int test::pipe(int *pfds, unsigned psize, int textmode) {
 #endif
 
 FILE *test::fopen(const char *filename, const char *mode) {
-  EMULATE_EINTR(fopen, nullptr);
+  EMULATE_EINTR(fopen, FMT_NULL);
   return ::fopen(filename, mode);
 }
 
@@ -216,7 +216,7 @@ TEST(UtilTest, GetPageSize) {
 
 TEST(FileTest, OpenRetry) {
   write_file("test", "there must be something here");
-  scoped_ptr<file> f{nullptr};
+  scoped_ptr<file> f{FMT_NULL};
   EXPECT_RETRY(f.reset(new file("test", file::RDONLY)),
                open, "cannot open file test");
 #ifndef _WIN32
@@ -232,7 +232,7 @@ TEST(FileTest, CloseNoRetryInDtor) {
   int saved_close_count = 0;
   EXPECT_WRITE(stderr, {
     close_count = 1;
-    f.reset(nullptr);
+    f.reset(FMT_NULL);
     saved_close_count = close_count;
     close_count = 0;
   }, format_system_error(EINTR, "cannot close file") + "\n");
@@ -385,7 +385,7 @@ TEST(FileTest, FdopenNoRetry) {
 
 TEST(BufferedFileTest, OpenRetry) {
   write_file("test", "there must be something here");
-  scoped_ptr<buffered_file> f{nullptr};
+  scoped_ptr<buffered_file> f{FMT_NULL};
   EXPECT_RETRY(f.reset(new buffered_file("test", "r")),
                fopen, "cannot open file test");
 #ifndef _WIN32
@@ -402,7 +402,7 @@ TEST(BufferedFileTest, CloseNoRetryInDtor) {
   int saved_fclose_count = 0;
   EXPECT_WRITE(stderr, {
     fclose_count = 1;
-    f.reset(nullptr);
+    f.reset(FMT_NULL);
     saved_fclose_count = fclose_count;
     fclose_count = 0;
   }, format_system_error(EINTR, "cannot close file") + "\n");
@@ -440,7 +440,7 @@ TEST(ScopedMock, Scope) {
     TestMock &copy = mock;
     static_cast<void>(copy);
   }
-  EXPECT_EQ(nullptr, TestMock::instance);
+  EXPECT_EQ(FMT_NULL, TestMock::instance);
 }
 
 #ifdef FMT_LOCALE
@@ -515,7 +515,7 @@ TEST(LocaleTest, Locale) {
 #endif
   ScopedMock<LocaleMock> mock;
   LocaleType impl = reinterpret_cast<LocaleType>(42);
-  EXPECT_CALL(mock, newlocale(LC_NUMERIC_MASK, StrEq("C"), nullptr))
+  EXPECT_CALL(mock, newlocale(LC_NUMERIC_MASK, StrEq("C"), FMT_NULL))
       .WillOnce(Return(impl));
   EXPECT_CALL(mock, freelocale(impl));
   fmt::Locale locale;
diff --git a/test/posix-test.cc b/test/posix-test.cc
index f23d06b3..4209b241 100644
--- a/test/posix-test.cc
+++ b/test/posix-test.cc
@@ -59,26 +59,26 @@ static void write(file &f, fmt::string_view s) {
 
 TEST(BufferedFileTest, DefaultCtor) {
   buffered_file f;
-  EXPECT_TRUE(f.get() == nullptr);
+  EXPECT_TRUE(f.get() == FMT_NULL);
 }
 
 TEST(BufferedFileTest, MoveCtor) {
   buffered_file bf = open_buffered_file();
   FILE *fp = bf.get();
-  EXPECT_TRUE(fp != nullptr);
+  EXPECT_TRUE(fp != FMT_NULL);
   buffered_file bf2(std::move(bf));
   EXPECT_EQ(fp, bf2.get());
-  EXPECT_TRUE(bf.get() == nullptr);
+  EXPECT_TRUE(bf.get() == FMT_NULL);
 }
 
 TEST(BufferedFileTest, MoveAssignment) {
   buffered_file bf = open_buffered_file();
   FILE *fp = bf.get();
-  EXPECT_TRUE(fp != nullptr);
+  EXPECT_TRUE(fp != FMT_NULL);
   buffered_file bf2;
   bf2 = std::move(bf);
   EXPECT_EQ(fp, bf2.get());
-  EXPECT_TRUE(bf.get() == nullptr);
+  EXPECT_TRUE(bf.get() == FMT_NULL);
 }
 
 TEST(BufferedFileTest, MoveAssignmentClosesFile) {
@@ -90,13 +90,13 @@ TEST(BufferedFileTest, MoveAssignmentClosesFile) {
 }
 
 TEST(BufferedFileTest, MoveFromTemporaryInCtor) {
-  FILE *fp = nullptr;
+  FILE *fp = FMT_NULL;
   buffered_file f(open_buffered_file(&fp));
   EXPECT_EQ(fp, f.get());
 }
 
 TEST(BufferedFileTest, MoveFromTemporaryInAssignment) {
-  FILE *fp = nullptr;
+  FILE *fp = FMT_NULL;
   buffered_file f;
   f = open_buffered_file(&fp);
   EXPECT_EQ(fp, f.get());
@@ -126,7 +126,7 @@ TEST(BufferedFileTest, CloseErrorInDtor) {
       // output in EXPECT_STDERR and the second close will break output
       // redirection.
       FMT_POSIX(close(f->fileno()));
-      SUPPRESS_ASSERT(f.reset(nullptr));
+      SUPPRESS_ASSERT(f.reset(FMT_NULL));
   }, format_system_error(EBADF, "cannot close file") + "\n");
 }
 
@@ -134,7 +134,7 @@ TEST(BufferedFileTest, Close) {
   buffered_file f = open_buffered_file();
   int fd = f.fileno();
   f.close();
-  EXPECT_TRUE(f.get() == nullptr);
+  EXPECT_TRUE(f.get() == FMT_NULL);
   EXPECT_TRUE(isclosed(fd));
 }
 
@@ -142,7 +142,7 @@ TEST(BufferedFileTest, CloseError) {
   buffered_file f = open_buffered_file();
   FMT_POSIX(close(f.fileno()));
   EXPECT_SYSTEM_ERROR_NOASSERT(f.close(), EBADF, "cannot close file");
-  EXPECT_TRUE(f.get() == nullptr);
+  EXPECT_TRUE(f.get() == FMT_NULL);
 }
 
 TEST(BufferedFileTest, Fileno) {
@@ -253,7 +253,7 @@ TEST(FileTest, CloseErrorInDtor) {
       // output in EXPECT_STDERR and the second close will break output
       // redirection.
       FMT_POSIX(close(f->descriptor()));
-      SUPPRESS_ASSERT(f.reset(nullptr));
+      SUPPRESS_ASSERT(f.reset(FMT_NULL));
   }, format_system_error(EBADF, "cannot close file") + "\n");
 }
 
diff --git a/test/printf-test.cc b/test/printf-test.cc
index f9208c16..22b28aca 100644
--- a/test/printf-test.cc
+++ b/test/printf-test.cc
@@ -426,11 +426,11 @@ TEST(PrintfTest, Char) {
 
 TEST(PrintfTest, String) {
   EXPECT_PRINTF("abc", "%s", "abc");
-  const char *null_str = nullptr;
+  const char *null_str = FMT_NULL;
   EXPECT_PRINTF("(null)", "%s", null_str);
   EXPECT_PRINTF("    (null)", "%10s", null_str);
   EXPECT_PRINTF(L"abc", L"%s", L"abc");
-  const wchar_t *null_wstr = nullptr;
+  const wchar_t *null_wstr = FMT_NULL;
   EXPECT_PRINTF(L"(null)", L"%s", null_wstr);
   EXPECT_PRINTF(L"    (null)", L"%10s", null_wstr);
 }
@@ -439,22 +439,22 @@ TEST(PrintfTest, Pointer) {
   int n;
   void *p = &n;
   EXPECT_PRINTF(fmt::format("{}", p), "%p", p);
-  p = nullptr;
+  p = FMT_NULL;
   EXPECT_PRINTF("(nil)", "%p", p);
   EXPECT_PRINTF("     (nil)", "%10p", p);
   const char *s = "test";
   EXPECT_PRINTF(fmt::format("{:p}", s), "%p", s);
-  const char *null_str = nullptr;
+  const char *null_str = FMT_NULL;
   EXPECT_PRINTF("(nil)", "%p", null_str);
 
   p = &n;
   EXPECT_PRINTF(fmt::format(L"{}", p), L"%p", p);
-  p = nullptr;
+  p = FMT_NULL;
   EXPECT_PRINTF(L"(nil)", L"%p", p);
   EXPECT_PRINTF(L"     (nil)", L"%10p", p);
   const wchar_t *w = L"test";
   EXPECT_PRINTF(fmt::format(L"{:p}", w), L"%p", w);
-  const wchar_t *null_wstr = nullptr;
+  const wchar_t *null_wstr = FMT_NULL;
   EXPECT_PRINTF(L"(nil)", L"%p", null_wstr);
 }
 
diff --git a/test/ranges-test.cc b/test/ranges-test.cc
index 3f02cbf5..77b4ced5 100644
--- a/test/ranges-test.cc
+++ b/test/ranges-test.cc
@@ -9,12 +9,11 @@
 // All Rights Reserved
 // {fmt} support for ranges, containers and types tuple interface.
 
-#include "fmt/ranges.h"
-
 /// Check if  'if constexpr' is supported.
 #if (__cplusplus > 201402L) || \
     (defined(_MSVC_LANG) && _MSVC_LANG > 201402L && _MSC_VER >= 1910)
 
+#include "fmt/ranges.h"
 #include "gtest.h"
 
 #include <vector>
diff --git a/test/time-test.cc b/test/time-test.cc
index bc05f24c..30957404 100644
--- a/test/time-test.cc
+++ b/test/time-test.cc
@@ -26,7 +26,7 @@ TEST(TimeTest, GrowBuffer) {
   for (int i = 0; i < 30; ++i)
     s += "%c";
   s += "}\n";
-  std::time_t t = std::time(nullptr);
+  std::time_t t = std::time(FMT_NULL);
   fmt::format(s, *std::localtime(&t));
 }
 
@@ -47,13 +47,13 @@ static bool EqualTime(const std::tm &lhs, const std::tm &rhs) {
 }
 
 TEST(TimeTest, LocalTime) {
-  std::time_t t = std::time(nullptr);
+  std::time_t t = std::time(FMT_NULL);
   std::tm tm = *std::localtime(&t);
   EXPECT_TRUE(EqualTime(tm, fmt::localtime(t)));
 }
 
 TEST(TimeTest, GMTime) {
-  std::time_t t = std::time(nullptr);
+  std::time_t t = std::time(FMT_NULL);
   std::tm tm = *std::gmtime(&t);
   EXPECT_TRUE(EqualTime(tm, fmt::gmtime(t)));
 }
diff --git a/test/util.h b/test/util.h
index c0af03c7..2b068d95 100644
--- a/test/util.h
+++ b/test/util.h
@@ -35,7 +35,7 @@ std::string get_system_error(int error_code);
 extern const char *const FILE_CONTENT;
 
 // Opens a buffered file for reading.
-fmt::buffered_file open_buffered_file(FILE **fp = nullptr);
+fmt::buffered_file open_buffered_file(FILE **fp = FMT_NULL);
 
 inline FILE *safe_fopen(const char *filename, const char *mode) {
 #if defined(_WIN32) && !defined(__MINGW32__)