diff --git a/ChangeLog b/ChangeLog
index 2eb8ed8c01..a4f28cb4c0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2001-10-10  Havoc Pennington  <hp@pobox.com>
+
+	* gdk/gdkwindow.c (gdk_window_new): set _NET_WM_PID
+
 2001-09-02  Abel Cheung  <maddog@linux.org.hk>
 
 	* configure.in (ALL_LINGUAS): zh_TW.Big5 -> zh_TW
diff --git a/ChangeLog.pre-2-0 b/ChangeLog.pre-2-0
index 2eb8ed8c01..a4f28cb4c0 100644
--- a/ChangeLog.pre-2-0
+++ b/ChangeLog.pre-2-0
@@ -1,3 +1,7 @@
+2001-10-10  Havoc Pennington  <hp@pobox.com>
+
+	* gdk/gdkwindow.c (gdk_window_new): set _NET_WM_PID
+
 2001-09-02  Abel Cheung  <maddog@linux.org.hk>
 
 	* configure.in (ALL_LINGUAS): zh_TW.Big5 -> zh_TW
diff --git a/ChangeLog.pre-2-10 b/ChangeLog.pre-2-10
index 2eb8ed8c01..a4f28cb4c0 100644
--- a/ChangeLog.pre-2-10
+++ b/ChangeLog.pre-2-10
@@ -1,3 +1,7 @@
+2001-10-10  Havoc Pennington  <hp@pobox.com>
+
+	* gdk/gdkwindow.c (gdk_window_new): set _NET_WM_PID
+
 2001-09-02  Abel Cheung  <maddog@linux.org.hk>
 
 	* configure.in (ALL_LINGUAS): zh_TW.Big5 -> zh_TW
diff --git a/ChangeLog.pre-2-2 b/ChangeLog.pre-2-2
index 2eb8ed8c01..a4f28cb4c0 100644
--- a/ChangeLog.pre-2-2
+++ b/ChangeLog.pre-2-2
@@ -1,3 +1,7 @@
+2001-10-10  Havoc Pennington  <hp@pobox.com>
+
+	* gdk/gdkwindow.c (gdk_window_new): set _NET_WM_PID
+
 2001-09-02  Abel Cheung  <maddog@linux.org.hk>
 
 	* configure.in (ALL_LINGUAS): zh_TW.Big5 -> zh_TW
diff --git a/ChangeLog.pre-2-4 b/ChangeLog.pre-2-4
index 2eb8ed8c01..a4f28cb4c0 100644
--- a/ChangeLog.pre-2-4
+++ b/ChangeLog.pre-2-4
@@ -1,3 +1,7 @@
+2001-10-10  Havoc Pennington  <hp@pobox.com>
+
+	* gdk/gdkwindow.c (gdk_window_new): set _NET_WM_PID
+
 2001-09-02  Abel Cheung  <maddog@linux.org.hk>
 
 	* configure.in (ALL_LINGUAS): zh_TW.Big5 -> zh_TW
diff --git a/ChangeLog.pre-2-6 b/ChangeLog.pre-2-6
index 2eb8ed8c01..a4f28cb4c0 100644
--- a/ChangeLog.pre-2-6
+++ b/ChangeLog.pre-2-6
@@ -1,3 +1,7 @@
+2001-10-10  Havoc Pennington  <hp@pobox.com>
+
+	* gdk/gdkwindow.c (gdk_window_new): set _NET_WM_PID
+
 2001-09-02  Abel Cheung  <maddog@linux.org.hk>
 
 	* configure.in (ALL_LINGUAS): zh_TW.Big5 -> zh_TW
diff --git a/ChangeLog.pre-2-8 b/ChangeLog.pre-2-8
index 2eb8ed8c01..a4f28cb4c0 100644
--- a/ChangeLog.pre-2-8
+++ b/ChangeLog.pre-2-8
@@ -1,3 +1,7 @@
+2001-10-10  Havoc Pennington  <hp@pobox.com>
+
+	* gdk/gdkwindow.c (gdk_window_new): set _NET_WM_PID
+
 2001-09-02  Abel Cheung  <maddog@linux.org.hk>
 
 	* configure.in (ALL_LINGUAS): zh_TW.Big5 -> zh_TW
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index 09eb7dfe8f..ba29a6310b 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -28,6 +28,9 @@
 #include <X11/Xutil.h>
 #include <X11/Xatom.h>
 #include <netinet/in.h>
+#include <sys/types.h>
+#include <unistd.h>
+
 #include "gdk.h"
 #include "config.h"
 #include "gdkinput.h"
@@ -488,6 +491,15 @@ gdk_window_new (GdkWindow     *parent,
       XFree (class_hint);
     }
   
+  {
+    gulong pid = getpid ();
+    
+    XChangeProperty (private->xdisplay, private->xwindow,
+                     gdk_atom_intern ("_NET_WM_PID", FALSE),
+                     XA_CARDINAL, 32,
+                     PropModeReplace,
+                     (guchar *)&pid, 1);
+  }
   
   return window;
 }