diff --git a/Makefile b/Makefile
index 775ee838c3..d9243aad9b 100644
--- a/Makefile
+++ b/Makefile
@@ -45,11 +45,6 @@ all::
 # Define NO_D_TYPE_IN_DIRENT if your platform defines DT_UNKNOWN but lacks
 # d_type in struct dirent (Cygwin 1.5, fixed in Cygwin 1.7).
 #
-# Define NO_C99_FORMAT if your formatted IO functions (printf/scanf et.al.)
-# do not support the 'size specifiers' introduced by C99, namely ll, hh,
-# j, z, t. (representing long long int, char, intmax_t, size_t, ptrdiff_t).
-# some C compilers supported these specifiers prior to C99 as an extension.
-#
 # Define NO_STRCASESTR if you don't have strcasestr.
 #
 # Define NO_MEMMEM if you don't have memmem.
@@ -870,7 +865,6 @@ ifeq ($(uname_S),SunOS)
 		NO_UNSETENV = YesPlease
 		NO_SETENV = YesPlease
 		NO_STRLCPY = YesPlease
-		NO_C99_FORMAT = YesPlease
 		NO_STRTOUMAX = YesPlease
 		GIT_TEST_CMP = cmp
 	endif
@@ -881,21 +875,18 @@ ifeq ($(uname_S),SunOS)
 		NO_UNSETENV = YesPlease
 		NO_SETENV = YesPlease
 		NO_STRLCPY = YesPlease
-		NO_C99_FORMAT = YesPlease
 		NO_STRTOUMAX = YesPlease
 		GIT_TEST_CMP = cmp
 	endif
 	ifeq ($(uname_R),5.8)
 		NO_UNSETENV = YesPlease
 		NO_SETENV = YesPlease
-		NO_C99_FORMAT = YesPlease
 		NO_STRTOUMAX = YesPlease
 		GIT_TEST_CMP = cmp
 	endif
 	ifeq ($(uname_R),5.9)
 		NO_UNSETENV = YesPlease
 		NO_SETENV = YesPlease
-		NO_C99_FORMAT = YesPlease
 		NO_STRTOUMAX = YesPlease
 		GIT_TEST_CMP = cmp
 	endif
@@ -1074,7 +1065,6 @@ ifeq ($(uname_S),Windows)
 	NO_MEMMEM = YesPlease
 	# NEEDS_LIBICONV = YesPlease
 	NO_ICONV = YesPlease
-	NO_C99_FORMAT = YesPlease
 	NO_STRTOUMAX = YesPlease
 	NO_STRTOULL = YesPlease
 	NO_MKDTEMP = YesPlease
@@ -1151,7 +1141,6 @@ ifneq (,$(findstring MINGW,$(uname_S)))
 	NO_MEMMEM = YesPlease
 	NEEDS_LIBICONV = YesPlease
 	OLD_ICONV = YesPlease
-	NO_C99_FORMAT = YesPlease
 	NO_STRTOUMAX = YesPlease
 	NO_MKDTEMP = YesPlease
 	NO_MKSTEMPS = YesPlease
@@ -1354,9 +1343,6 @@ endif
 ifdef NO_NSEC
 	BASIC_CFLAGS += -DNO_NSEC
 endif
-ifdef NO_C99_FORMAT
-	BASIC_CFLAGS += -DNO_C99_FORMAT
-endif
 ifdef SNPRINTF_RETURNS_BOGUS
 	COMPAT_CFLAGS += -DSNPRINTF_RETURNS_BOGUS
 	COMPAT_OBJS += compat/snprintf.o
diff --git a/alloc.c b/alloc.c
index 6ef6753d18..aeae55c976 100644
--- a/alloc.c
+++ b/alloc.c
@@ -51,19 +51,12 @@ DEFINE_ALLOCATOR(commit, struct commit)
 DEFINE_ALLOCATOR(tag, struct tag)
 DEFINE_ALLOCATOR(object, union any_object)
 
-#ifdef NO_C99_FORMAT
-#define SZ_FMT "%u"
-#else
-#define SZ_FMT "%zu"
-#endif
-
 static void report(const char *name, unsigned int count, size_t size)
 {
-    fprintf(stderr, "%10s: %8u (" SZ_FMT " kB)\n", name, count, size);
+	fprintf(stderr, "%10s: %8u (%"PRIuMAX" kB)\n",
+			name, count, (uintmax_t) size);
 }
 
-#undef SZ_FMT
-
 #define REPORT(name)	\
     report(#name, name##_allocs, name##_allocs*sizeof(struct name) >> 10)
 
diff --git a/config.mak.in b/config.mak.in
index 9614973057..e378534cbd 100644
--- a/config.mak.in
+++ b/config.mak.in
@@ -43,7 +43,6 @@ NO_D_INO_IN_DIRENT=@NO_D_INO_IN_DIRENT@
 NO_D_TYPE_IN_DIRENT=@NO_D_TYPE_IN_DIRENT@
 NO_SOCKADDR_STORAGE=@NO_SOCKADDR_STORAGE@
 NO_IPV6=@NO_IPV6@
-NO_C99_FORMAT=@NO_C99_FORMAT@
 NO_HSTRERROR=@NO_HSTRERROR@
 NO_STRCASESTR=@NO_STRCASESTR@
 NO_STRTOK_R=@NO_STRTOK_R@
diff --git a/configure.ac b/configure.ac
index 20039c546f..dd0790725b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -686,30 +686,6 @@ AC_CHECK_TYPE([struct addrinfo],[
 ])
 AC_SUBST(NO_IPV6)
 #
-# Define NO_C99_FORMAT if your formatted IO functions (printf/scanf et.al.)
-# do not support the 'size specifiers' introduced by C99, namely ll, hh,
-# j, z, t. (representing long long int, char, intmax_t, size_t, ptrdiff_t).
-# some C compilers supported these specifiers prior to C99 as an extension.
-AC_CACHE_CHECK([whether formatted IO functions support C99 size specifiers],
- [ac_cv_c_c99_format],
-[# Actually git uses only %z (%zu) in alloc.c, and %t (%td) in mktag.c
-AC_RUN_IFELSE(
-	[AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT],
-		[[char buf[64];
-		if (sprintf(buf, "%lld%hhd%jd%zd%td", (long long int)1, (char)2, (intmax_t)3, (size_t)4, (ptrdiff_t)5) != 5)
-		  return 1;
-		else if (strcmp(buf, "12345"))
-		  return 2;]])],
-	[ac_cv_c_c99_format=yes],
-	[ac_cv_c_c99_format=no])
-])
-if test $ac_cv_c_c99_format = no; then
-	NO_C99_FORMAT=YesPlease
-else
-	NO_C99_FORMAT=
-fi
-AC_SUBST(NO_C99_FORMAT)
-#
 # Define NO_REGEX if you have no or inferior regex support in your C library.
 AC_CACHE_CHECK([whether the platform regex can handle null bytes],
  [ac_cv_c_excellent_regex], [
diff --git a/sha1_file.c b/sha1_file.c
index 27730c334c..ea99f6f313 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -25,13 +25,8 @@
 #endif
 #endif
 
-#ifdef NO_C99_FORMAT
-#define SZ_FMT "lu"
-static unsigned long sz_fmt(size_t s) { return (unsigned long)s; }
-#else
-#define SZ_FMT "zu"
-static size_t sz_fmt(size_t s) { return s; }
-#endif
+#define SZ_FMT PRIuMAX
+static inline uintmax_t sz_fmt(size_t s) { return s; }
 
 const unsigned char null_sha1[20];