diff --git a/dix/dispatch.c b/dix/dispatch.c
index 0a6168f6c..6d0bc6c6f 100644
--- a/dix/dispatch.c
+++ b/dix/dispatch.c
@@ -120,7 +120,6 @@ Equipment Corporation.
 #include "os/screensaver.h"
 
 #include "windowstr.h"
-#include "ddx.h"
 #include "dixfontstr.h"
 #include "gcstruct.h"
 #include "colormapst.h"
diff --git a/dix/main.c b/dix/main.c
index 2d6735add..0fb762071 100644
--- a/dix/main.c
+++ b/dix/main.c
@@ -112,7 +112,6 @@ Equipment Corporation.
 #include "colormapst.h"
 #include "cursorstr.h"
 #include "servermd.h"
-#include "ddx.h"
 #include "dixfont.h"
 #include "extnsionst.h"
 #include "privates.h"
diff --git a/hw/kdrive/ephyr/ephyrinit.c b/hw/kdrive/ephyr/ephyrinit.c
index 742f98ac1..9306f3367 100644
--- a/hw/kdrive/ephyr/ephyrinit.c
+++ b/hw/kdrive/ephyr/ephyrinit.c
@@ -30,7 +30,6 @@
 #include "os/ddx_priv.h"
 #include "os/osdep.h"
 
-#include "ddx.h"
 #include "ephyr.h"
 #include "ephyrlog.h"
 #include "glx_extinit.h"
diff --git a/hw/kdrive/src/kdrive.c b/hw/kdrive/src/kdrive.c
index 761e57dba..1a16e9b05 100644
--- a/hw/kdrive/src/kdrive.c
+++ b/hw/kdrive/src/kdrive.c
@@ -26,7 +26,6 @@
 #include "dix/screenint_priv.h"
 #include "os/cmdline.h"
 #include "os/ddx_priv.h"
-
 #include "os/osdep.h"
 
 #include "kdrive.h"
diff --git a/hw/vfb/InitOutput.c b/hw/vfb/InitOutput.c
index d5ef77e18..4a448a5ae 100644
--- a/hw/vfb/InitOutput.c
+++ b/hw/vfb/InitOutput.c
@@ -69,7 +69,6 @@ from The Open Group.
 #include <sys/ipc.h>
 #include <sys/shm.h>
 #endif                          /* MITSHM */
-#include "ddx.h"
 #include "dix.h"
 #include "miline.h"
 #include "glx_extinit.h"
diff --git a/hw/xfree86/common/xf86Configure.c b/hw/xfree86/common/xf86Configure.c
index 75032b642..923b73516 100644
--- a/hw/xfree86/common/xf86Configure.c
+++ b/hw/xfree86/common/xf86Configure.c
@@ -32,7 +32,6 @@
 #include "os/ddx_priv.h"
 #include "os/osdep.h"
 
-#include "ddx.h"
 #include "xf86.h"
 #include "xf86Config.h"
 #include "xf86_OSlib.h"
diff --git a/hw/xnest/Args.c b/hw/xnest/Args.c
index c83666c4e..8f448babb 100644
--- a/hw/xnest/Args.c
+++ b/hw/xnest/Args.c
@@ -25,7 +25,6 @@ is" without express or implied warranty.
 #include "misc.h"
 #include "scrnintstr.h"
 #include "servermd.h"
-#include "ddx.h"
 
 #include "xnest-xcb.h"
 
diff --git a/hw/xnest/Init.c b/hw/xnest/Init.c
index f5f9dd886..ccd663903 100644
--- a/hw/xnest/Init.c
+++ b/hw/xnest/Init.c
@@ -25,7 +25,6 @@ is" without express or implied warranty.
 #include "os/ddx_priv.h"
 #include "os/osdep.h"
 
-#include "ddx.h"
 #include "screenint.h"
 #include "input.h"
 #include "misc.h"
diff --git a/hw/xquartz/darwin.c b/hw/xquartz/darwin.c
index f2f30d2d0..caadd8944 100644
--- a/hw/xquartz/darwin.c
+++ b/hw/xquartz/darwin.c
@@ -46,7 +46,6 @@
 #include "micmap.h"             // mi colormap code
 #include "fb.h"                 // fb framebuffer code
 #include "globals.h"
-#include "ddx.h"
 #include "dix.h"
 #include "xkbsrv.h"
 
diff --git a/hw/xwayland/xwayland.c b/hw/xwayland/xwayland.c
index 889452c22..427ccf3f1 100644
--- a/hw/xwayland/xwayland.c
+++ b/hw/xwayland/xwayland.c
@@ -51,7 +51,6 @@
 #include <glx_extinit.h>
 #include <opaque.h>
 #include <os.h>
-#include "ddx.h"
 #include <propertyst.h>
 #include <version-config.h>
 
diff --git a/hw/xwin/winprocarg.c b/hw/xwin/winprocarg.c
index d32c705cf..e88dca235 100644
--- a/hw/xwin/winprocarg.c
+++ b/hw/xwin/winprocarg.c
@@ -36,6 +36,7 @@ from The Open Group.
 #endif
 
 #include "os/cmdline.h"
+#include "os/ddx_priv.h"
 #include "os/osdep.h"
 #include "os/ddx_priv.h"
 
@@ -47,7 +48,6 @@ from The Open Group.
 #include "winprefs.h"
 
 #include "winclipboard/winclipboard.h"
-#include "ddx.h"
 
 /*
  * Function prototypes
diff --git a/meson.build b/meson.build
index 50dd72c91..77b2f64b4 100644
--- a/meson.build
+++ b/meson.build
@@ -654,7 +654,6 @@ inc = include_directories(
     'dix',
     'dri3',
     'include',
-    'os',
     'present',
     'randr',
     'render',
diff --git a/os/ddx.h b/os/ddx.h
deleted file mode 100644
index 1f90e099d..000000000
--- a/os/ddx.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/* SPDX-License-Identifier: MIT OR X11
- *
- * Copyright © 2024 Enrico Weigelt, metux IT consult <info@metux.net>
- */
-#ifndef _XSERVER_OS_DDX_H
-#define _XSERVER_OS_DDX_H
-
-#include "os.h"
-
-/* callbacks of the DDX, which are called by DIX or OS layer.
-   DDX's need to implement these in order to handle DDX specific things.
-*/
-
-/* called before server reset */
-void ddxBeforeReset(void);
-
-/* called by ProcessCommandLine, so DDX can catch cmdline args */
-int ddxProcessArgument(int argc, char *argv[], int i);
-
-/* print DDX specific usage message */
-void ddxUseMsg(void);
-
-void ddxGiveUp(enum ExitCode error);
-
-void ddxInputThreadInit(void);
-
-#endif /* _XSERVER_OS_DDX_H */
diff --git a/os/inputthread.c b/os/inputthread.c
index 623648256..8313e8ab3 100644
--- a/os/inputthread.c
+++ b/os/inputthread.c
@@ -33,6 +33,7 @@
 #include <unistd.h>
 #include <pthread.h>
 
+#include "os/ddx_priv.h"
 #include "dix/input_priv.h"
 #include "os/ddx_priv.h"
 
diff --git a/os/log.c b/os/log.c
index 28833d642..281e3a384 100644
--- a/os/log.c
+++ b/os/log.c
@@ -96,7 +96,6 @@ OR PERFORMANCE OF THIS SOFTWARE.
 #include "os/osdep.h"
 
 #include "opaque.h"
-#include "ddx.h"
 
 #ifdef XF86BIGFONT
 #include "xf86bigfontsrv.h"
diff --git a/os/utils.c b/os/utils.c
index e945560b0..de49e2b35 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -116,7 +116,6 @@ __stdcall unsigned long GetTickCount(void);
 #include "xkbsrv.h"
 #include "picture.h"
 #include "miinitext.h"
-#include "ddx.h"
 #include "present.h"
 #include "dixstruct_priv.h"
 #include "dpmsproc.h"