diff --git a/config.h.meson b/config.h.meson
index 3e6c518478..b917bb5320 100644
--- a/config.h.meson
+++ b/config.h.meson
@@ -212,9 +212,6 @@
 /* Define to 1 if you have the `_NSGetEnviron' function. */
 #mesondefine HAVE__NSGETENVIRON
 
-/* Define if <X11/extensions/XIproto.h> needed for xReply */
-#mesondefine NEED_XIPROTO_H_FOR_XREPLY
-
 /* Define to the address where bug reports for this package should be sent. */
 #mesondefine PACKAGE_BUGREPORT
 
diff --git a/config.h.win32.in b/config.h.win32.in
index 3a5219e5a2..b6d8062c32 100644
--- a/config.h.win32.in
+++ b/config.h.win32.in
@@ -255,9 +255,6 @@
    */
 #define LT_OBJDIR ".libs/"
 
-/* Define if <X11/extensions/XIproto.h> needed for xReply */
-/* #undef NEED_XIPROTO_H_FOR_XREPLY */
-
 /* Define to 1 if your C compiler doesn't accept -c and -o together. */
 #ifndef _MSC_VER
 /* #undef NO_MINUS_C_MINUS_O */
diff --git a/configure.ac b/configure.ac
index 362ea73b0c..6acd65e9b1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1055,17 +1055,6 @@ if test "x$enable_x11_backend" = xyes; then
   AC_CHECK_FUNC(XextFindDisplay, :,
                 AC_MSG_ERROR([*** libX11 and libXext not found. Check 'config.log' for more details.]))
 
-  # Check if <X11/extensions/XIproto.h> is needed for xReply.
-
-  AC_CHECK_TYPE([xReply], ,
-                [AC_CHECK_TYPE([xReply],
-                               [AC_DEFINE([NEED_XIPROTO_H_FOR_XREPLY], 1,
-                                          [Define if <X11/extensions/XIproto.h> needed for xReply])],
-                               [AC_MSG_ERROR([xReply type unavailable. X11 is too old])],
-                               [[#include <X11/extensions/XIproto.h>
-                                 #include <X11/Xlibint.h>]])],
-                [[#include <X11/Xlibint.h>]])
-
   # Check for XKB support.
 
   if test "x$enable_xkb" = "xyes"; then
diff --git a/gdk/x11/gdkasync.c b/gdk/x11/gdkasync.c
index 51a088fc6d..69632136bf 100644
--- a/gdk/x11/gdkasync.c
+++ b/gdk/x11/gdkasync.c
@@ -46,10 +46,6 @@ in this Software without prior written authorization from The Open Group.
 #include "gdkasync.h"
 #include "gdkprivate-x11.h"
 
-#ifdef NEED_XIPROTO_H_FOR_XREPLY
-#include <X11/extensions/XIproto.h>
-#endif
-
 #include <X11/Xlibint.h>