diff --git a/ac_check_sendfile.m4 b/ac_check_sendfile.m4
deleted file mode 100644
index 12605d588..000000000
--- a/ac_check_sendfile.m4
+++ /dev/null
@@ -1,63 +0,0 @@
-AC_DEFUN([AC_CHECK_SENDFILE],[
-AC_MSG_CHECKING([whether sendfile() is supported and what prototype it has])
-
-saved_CFLAGS="$CFLAGS"
-CFLAGS="$CFLAGS -Werror-implicit-function-declaration"
-ac_sendfile_supported=no
-AC_TRY_LINK([#include <sys/sendfile.h>
-               #include <stdio.h>],
-       [sendfile(1, 1, NULL, 0);],
-       [
-               AC_DEFINE(HAVE_SENDFILE4_SUPPORT, 1,
-                       [Define this if Linux/Solaris sendfile() is supported])
-               AC_MSG_RESULT([Linux sendfile()])
-               ac_sendfile_supported=yes
-       ], [])
-
-if test x$ac_sendfile_supported = xno; then
-       dnl Checking wether we need libsendfile
-       dnl Presumably on Solaris
-       AC_CHECK_LIB(sendfile, sendfile,
-               [
-                       AC_DEFINE(HAVE_SENDFILE4_SUPPORT, 1,
-                               [Define this if Linux/Solaris sendfile() is supported])
-                       SENDFILE_LIBS="-lsendfile"
-                       AC_SUBST(SENDFILE_LIBS)
-                       AC_MSG_RESULT([Solaris sendfile()])
-                       ac_sendfile_supported=yes
-               ], [])
-fi
-
-if test x$ac_sendfile_supported = xno; then
-       dnl Checking wether we have FreeBSD-like sendfile() support.
-       AC_TRY_LINK([#include <sys/socket.h>
-                       #include <stdio.h>],
-               [sendfile(1, 1, 0, 0, NULL, NULL, 0);],
-               [
-                       AC_DEFINE(HAVE_SENDFILE7_SUPPORT, 1,
-                               [Define this if FreeBSD sendfile() is supported])
-                       AC_MSG_RESULT([FreeBSD sendfile()])
-                       ac_sendfile_supported=yes
-               ], [])
-fi
-
-if test x$ac_sendfile_supported = xno; then
-       dnl Checking wether we have MacOS-like sendfile() support.
-       AC_TRY_LINK([#include <sys/socket.h>
-                       #include <stdio.h>
-                       #include <sys/uio.h>],
-               [sendfile(1, 1, 0, NULL, NULL, 0);],
-               [
-                       AC_DEFINE(HAVE_SENDFILE6_SUPPORT, 1,
-                               [Define this if MacOS sendfile() is supported])
-                       AC_MSG_RESULT([MacOS sendfile()])
-                       ac_sendfile_supported=yes
-               ], [])
-fi
-
-CFLAGS="$saved_CFLAGS"
-
-if test x$ac_sendfile_supported = xno; then
-       AC_MSG_RESULT([no sendfile() support, using read/send])
-fi
-])