diff --git a/Xext/dpms.c b/Xext/dpms.c
index b582669f76..8e3e2d9fdf 100644
--- a/Xext/dpms.c
+++ b/Xext/dpms.c
@@ -39,6 +39,7 @@ Equipment Corporation.
 #include "miext/extinit_priv.h"
 #include "os/screensaver.h"
 #include "os/osdep.h"
+#include "Xext/dpms/dpms_priv.h"
 #include "Xext/geext_priv.h"
 
 #include "misc.h"
@@ -46,7 +47,6 @@ Equipment Corporation.
 #include "dixstruct.h"
 #include "extnsionst.h"
 #include "opaque.h"
-#include "dpmsproc.h"
 #include "scrnintstr.h"
 #include "windowstr.h"
 #include "protocol-versions.h"
diff --git a/Xext/dpms/dpms_priv.h b/Xext/dpms/dpms_priv.h
new file mode 100644
index 0000000000..3a1026c238
--- /dev/null
+++ b/Xext/dpms/dpms_priv.h
@@ -0,0 +1,122 @@
+/* SPDX-License-Identifier: MIT OR X11 OR AGPL-3.0-or-later
+ *
+ * DPMS (Display Power Management Signaling) — interface between the
+ * DPMS extension and other parts (DIX, DDX, OS).
+ *
+ * Copyright © 2026 Enrico Weigelt, metux IT consult <info@metux.net>
+ *
+ * This header is NOT part of the driver API.  Drivers must NOT
+ * include it.  It is for use by the extension, DIX, and DDX only.
+ *
+ * DDX is assumed to provide entry point via ScreenRec->DPMS() and set
+ * several variables (eg. DPMSStandbyTime, DPMSDisabledSwitch, etc)
+ * on startup.
+ *
+ * Timeout variables (DPMSStandbyTime, DPMSSuspendTime, DPMSOffTime)
+ * are in milliseconds.  They are initialised to ~0 (UINT32_MAX) in
+ * Xext/dpms.c, which the extension treats as "use ScreenSaverTime".
+ * The DDX may override them during InitOutput (e.g. xf86Config.c
+ * reads them from the command line / config file and converts from
+ * minutes to milliseconds).
+ *
+ * Power levels are defined in <X11/extensions/dpmsconst.h>:
+ *   DPMSModeOn      0   full power
+ *   DPMSModeStandby 1   minimal signal, fast resume
+ *   DPMSModeSuspend 2   deeper sleep, slower resume
+ *   DPMSModeOff     3   most power saving
+ */
+
+#ifndef _DPMS_PRIV_H_
+#define _DPMS_PRIV_H_
+
+#include <dix-config.h>
+
+#include "dixstruct.h"
+
+/**
+ * Set a new DPMS power level for every screen.
+ *
+ * Called by:
+ *   - WaitFor.c   (timer-driven automatic transitions)
+ *   - mieq.c      (any input event wakes the displays)
+ *   - xf86Init.c  (abort path — restore video before dying)
+ *   - xf86Events.c(VT switch — restore before leaving VT)
+ *   - dpms.c      (Disable, ForceLevel, CloseDown)
+ *
+ * Implementation:
+ *   Saves old DPMSPowerLevel, updates it to @level, co-ordinates
+ *   with the screen saver (blank/unblank if needed), then calls
+ *   walkScreen->DPMS(walkScreen, level) for every screen whose
+ *   DPMS callback is non-NULL.
+ *
+ * @client  the client requesting the change (may be serverClient)
+ * @level   one of DPMSModeOn/Standby/Suspend/Off
+ * @return  Success on success, or a dixSaveScreens error code.
+ */
+extern int DPMSSet(ClientPtr client, int level);
+
+/**
+ * Query whether DPMS is supported by any screen.
+ *
+ * Returns TRUE if at least one screen (or GPU screen) has a non-NULL
+ * DPMS function pointer.  Called during DPMSExtensionInit to decide
+ * whether to register the extension at all, and by the Info request
+ * to report the DPMS state.
+ */
+extern Bool DPMSSupported(void);
+
+/**
+ * Standby timeout in milliseconds.
+ *
+ * The idle time after which the server transitions to DPMS standby
+ * mode.  -1 (UINT32_MAX) at init; DPMSExtensionInit falls back to
+ * ScreenSaverTime.  The DDX may set this via configuration
+ * (e.g. xf86Config reads the "StandbyTime" option).
+ */
+extern CARD32 DPMSStandbyTime;
+
+/**
+ * Suspend timeout in milliseconds.
+ *
+ * The idle time after which the server transitions to DPMS suspend
+ * mode.  Semantics match DPMSStandbyTime.
+ */
+extern CARD32 DPMSSuspendTime;
+
+/**
+ * Off timeout in milliseconds.
+ *
+ * The idle time after which the server transitions to DPMS off
+ * mode.  Semantics match DPMSStandbyTime.
+ */
+extern CARD32 DPMSOffTime;
+
+/**
+ * Current DPMS power level.
+ *
+ * One of DPMSModeOn (0), DPMSModeStandby (1), DPMSModeSuspend (2),
+ * or DPMSModeOff (3).  Modified by DPMSSet() and queried by
+ * WaitFor.c (for timeout scheduling), mieq.c (wake on input),
+ * Xext/saver.c (coexistence with screen saver), xf86Init.c and
+ * xf86Events.c (restore before abort/VT switch).
+ */
+extern CARD16 DPMSPowerLevel;
+
+/**
+ * Whether the DPMS extension is currently enabled.
+ *
+ * Set to DPMSSupported() during DPMSExtensionInit.  May be toggled
+ * by the DPMS Enable/Disable protocol requests.  When FALSE, the
+ * timeout machinery in WaitFor.c skips DPMS transitions entirely.
+ */
+extern Bool DPMSEnabled;
+
+/**
+ * Set TRUE when the "-dpms" command-line flag is used.
+ *
+ * Checked by the DDX (xf86DPMSInit) to suppress DPMS initialisation
+ * even when the config file requests it.  Set by ddxProcessArgument().
+ */
+extern Bool DPMSDisabledSwitch;
+
+#endif
diff --git a/Xext/dpmsproc.h b/Xext/dpmsproc.h
deleted file mode 100644
index 9994e5103d..0000000000
--- a/Xext/dpmsproc.h
+++ /dev/null
@@ -1,20 +0,0 @@
-/* Prototypes for functions that the DDX must provide */
-
-#ifndef _DPMSPROC_H_
-#define _DPMSPROC_H_
-
-#include <dix-config.h>
-
-#include "dixstruct.h"
-
-extern int DPMSSet(ClientPtr client, int level);
-extern Bool DPMSSupported(void);
-
-extern CARD32 DPMSStandbyTime;
-extern CARD32 DPMSSuspendTime;
-extern CARD32 DPMSOffTime;
-extern CARD16 DPMSPowerLevel;
-extern Bool DPMSEnabled;
-extern Bool DPMSDisabledSwitch;
-
-#endif
diff --git a/Xext/saver.c b/Xext/saver.c
index 8a5f028f6f..8f0571921b 100644
--- a/Xext/saver.c
+++ b/Xext/saver.c
@@ -44,6 +44,9 @@ in this Software without prior written authorization from the X Consortium.
 #include "miext/extinit_priv.h"
 #include "os/osdep.h"
 #include "os/screensaver.h"
+#ifdef DPMSExtension
+#include "Xext/dpms/dpms_priv.h"
+#endif
 #include "Xext/panoramiX.h"
 #include "Xext/panoramiXsrv.h"
 
@@ -61,7 +64,6 @@ in this Software without prior written authorization from the X Consortium.
 #include "inputstr.h"
 #ifdef DPMSExtension
 #include <X11/extensions/dpmsconst.h>
-#include "dpmsproc.h"
 #endif
 #include "protocol-versions.h"
 
diff --git a/dix/main.c b/dix/main.c
index 8c55f11967..397a6fd804 100644
--- a/dix/main.c
+++ b/dix/main.c
@@ -104,6 +104,9 @@ Equipment Corporation.
 #include "os/osdep.h"
 #include "os/screensaver.h"
 #include "os/serverlock.h"
+#ifdef DPMSExtension
+#include "Xext/dpms/dpms_priv.h"
+#endif
 #include "Xext/panoramiXsrv.h"
 
 #include "scrnintstr.h"
@@ -123,7 +126,6 @@ Equipment Corporation.
 
 #ifdef DPMSExtension
 #include <X11/extensions/dpmsconst.h>
-#include "dpmsproc.h"
 #endif
 
 extern void Dispatch(void);
diff --git a/hw/kdrive/src/kdrive.c b/hw/kdrive/src/kdrive.c
index 297f297149..2df1a5ec49 100644
--- a/hw/kdrive/src/kdrive.c
+++ b/hw/kdrive/src/kdrive.c
@@ -32,6 +32,9 @@
 #include "os/cmdline.h"
 #include "os/ddx_priv.h"
 #include "os/osdep.h"
+#ifdef DPMSExtension
+#include "Xext/dpms/dpms_priv.h"
+#endif
 
 #include "kdrive.h"
 #include <dixstruct.h>
@@ -49,10 +52,6 @@
 #include "kxv.h"
 #endif
 
-#ifdef DPMSExtension
-#include "dpmsproc.h"
-#endif
-
 #ifdef HAVE_EXECINFO_H
 #include <execinfo.h>
 #endif
diff --git a/hw/xfree86/common/xf86Config.c b/hw/xfree86/common/xf86Config.c
index 79d46569a7..0de1216dcd 100644
--- a/hw/xfree86/common/xf86Config.c
+++ b/hw/xfree86/common/xf86Config.c
@@ -55,6 +55,9 @@
 #include "os/log_priv.h"
 #include "os/osdep.h"
 #include "xkb/xkbsrv_priv.h"
+#ifdef DPMSExtension
+#include "Xext/dpms/dpms_priv.h"
+#endif
 
 #include "xf86_priv.h"
 #include "xf86Modes.h"
@@ -72,9 +75,6 @@
 #include "xf86Xinput_priv.h"
 
 #include "picture.h"
-#ifdef DPMSExtension
-#include "dpmsproc.h"
-#endif
 
 /*
  * These paths define the way the config file search is done.  The escape
diff --git a/hw/xfree86/common/xf86DPMS.c b/hw/xfree86/common/xf86DPMS.c
index 4f36964163..4b21fb77e3 100644
--- a/hw/xfree86/common/xf86DPMS.c
+++ b/hw/xfree86/common/xf86DPMS.c
@@ -36,10 +36,15 @@
 #include "xf86.h"
 #include "xf86Priv.h"
 #include "xf86Opt_priv.h"
+
 #ifdef DPMSExtension
 #include <X11/extensions/dpmsconst.h>
-#include "dpmsproc.h"
 #endif
+
+#ifdef DPMSExtension
+#include "Xext/dpms/dpms_priv.h"
+#endif
+
 #include "xf86VGAarbiter_priv.h"
 
 #ifdef DPMSExtension
diff --git a/hw/xfree86/common/xf86Events.c b/hw/xfree86/common/xf86Events.c
index 4bf730959f..fdaf28e1b5 100644
--- a/hw/xfree86/common/xf86Events.c
+++ b/hw/xfree86/common/xf86Events.c
@@ -64,6 +64,9 @@
 #include "hw/xfree86/common/action_priv.h"
 #include "mi/mi_priv.h"
 #include "os/log_priv.h"
+#ifdef DPMSExtension
+#include "Xext/dpms/dpms_priv.h"
+#endif
 
 #include "misc.h"
 #include "xf86_priv.h"
@@ -85,7 +88,6 @@
 
 #ifdef DPMSExtension
 #include <X11/extensions/dpmsconst.h>
-#include "dpmsproc.h"
 #endif
 
 #include "../os-support/linux/systemd-logind.h"
diff --git a/hw/xfree86/common/xf86Init.c b/hw/xfree86/common/xf86Init.c
index c4427df803..994a7b93d3 100644
--- a/hw/xfree86/common/xf86Init.c
+++ b/hw/xfree86/common/xf86Init.c
@@ -60,6 +60,9 @@
 #include "os/log_priv.h"
 #include "os/osdep.h"
 #include "randr/randrstr_priv.h"
+#ifdef DPMSExtension
+#include "Xext/dpms/dpms_priv.h"
+#endif
 
 #include "servermd.h"
 #include "windowstr.h"
@@ -89,7 +92,6 @@
 
 #ifdef DPMSExtension
 #include <X11/extensions/dpmsconst.h>
-#include "dpmsproc.h"
 #endif
 
 #ifdef __linux__
diff --git a/hw/xnest/Init.c b/hw/xnest/Init.c
index bb55e3f662..0d46b3c228 100644
--- a/hw/xnest/Init.c
+++ b/hw/xnest/Init.c
@@ -26,6 +26,9 @@ is" without express or implied warranty.
 #include "os/ddx_priv.h"
 #include "os/log_priv.h"
 #include "os/osdep.h"
+#ifdef DPMSExtension
+#include "Xext/dpms/dpms_priv.h"
+#endif
 
 #include "screenint.h"
 #include "input.h"
@@ -47,9 +50,6 @@ is" without express or implied warranty.
 #include "Drawable.h"
 #include "XNGC.h"
 #include "XNFont.h"
-#ifdef DPMSExtension
-#include "dpmsproc.h"
-#endif
 
 Bool xnestDoFullGeneration = TRUE;
 
diff --git a/hw/xwin/InitOutput.c b/hw/xwin/InitOutput.c
index 9f81a941b7..2c21ed46b3 100644
--- a/hw/xwin/InitOutput.c
+++ b/hw/xwin/InitOutput.c
@@ -39,13 +39,13 @@ from The Open Group.
 #include "os/log_priv.h"
 #include "os/osdep.h"
 #include "xkb/xkbsrv_priv.h"
+#ifdef DPMSExtension
+#include "Xext/dpms/dpms_priv.h"
+#endif
 
 #include "winmsg.h"
 #include "winconfig.h"
 #include "winprefs.h"
-#ifdef DPMSExtension
-#include "dpmsproc.h"
-#endif
 #ifdef __CYGWIN__
 #include <mntent.h>
 #endif
diff --git a/mi/mieq.c b/mi/mieq.c
index 269156fb3b..d421e9c93e 100644
--- a/mi/mieq.c
+++ b/mi/mieq.c
@@ -49,9 +49,12 @@ in this Software without prior written authorization from The Open Group.
 #include   "mi/mi_priv.h"
 #include   "mi/mipointer_priv.h"
 #include   "os/bug_priv.h"
-#include   "os/screensaver.h"
+#include "os/screensaver.h"
+#ifdef DPMSExtension
+#include "Xext/dpms/dpms_priv.h"
+#endif
 
-#include   "misc.h"
+#include "misc.h"
 #include   "windowstr.h"
 #include   "pixmapstr.h"
 #include   "inputstr.h"
@@ -60,7 +63,6 @@ in this Software without prior written authorization from The Open Group.
 #include   "eventstr.h"
 
 #ifdef DPMSExtension
-#include "dpmsproc.h"
 #include <X11/extensions/dpmsconst.h>
 #endif
 
diff --git a/os/WaitFor.c b/os/WaitFor.c
index 992962df4b..78d435a0b8 100644
--- a/os/WaitFor.c
+++ b/os/WaitFor.c
@@ -68,14 +68,14 @@ SOFTWARE.
 #include "os/client_priv.h"
 #include "os/ossock.h"
 #include "os/screensaver.h"
+#ifdef DPMSExtension
+#include "Xext/dpms/dpms_priv.h"
+#endif
 
 #include "misc.h"
 #include "osdep.h"
 #include "dixstruct_priv.h"
 #include "globals.h"
-#ifdef DPMSExtension
-#include "dpmsproc.h"
-#endif
 
 #ifdef WIN32
 /* Error codes from windows sockets differ from fileio error codes  */
diff --git a/os/utils.c b/os/utils.c
index 9525d4ae00..81834f8814 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -118,6 +118,7 @@ __stdcall unsigned long GetTickCount(void);
 #include "os/serverlock.h"
 #include "os/xhostname.h"
 #include "present/present_priv.h"
+#include "Xext/dpms/dpms_priv.h"
 #include "Xext/xf86bigfontsrv.h" /* XF86BigfontCleanup() */
 #include "xkb/xkbsrv_priv.h"
 
@@ -125,7 +126,6 @@ __stdcall unsigned long GetTickCount(void);
 #include "picture.h"
 #include "miinitext.h"
 #include "dixstruct_priv.h"
-#include "dpmsproc.h"
 
 #define X_INCLUDE_NETDB_H
 #include <X11/Xos_r.h>