diff --git a/src/gd3.x11/createwindo3.c b/src/gd3.x11/createwindo3.c
index 89dbb23..b8501bb 100755
--- a/src/gd3.x11/createwindo3.c
+++ b/src/gd3.x11/createwindo3.c
@@ -71,6 +71,7 @@ createwindow3(win_num, xmin_vp, xmax_vp, ymin_vp, ymax_vp, nerr)
   int xul_p, yul_p;
   unsigned int width_p, height_p;
   char title_label[32], *ptitle_label;
+  Atom wm_delete_window;
   XSetWindowAttributes winatt;
   XGCValues xgcval, xgccurs, xgcdef,xgcicon;
   unsigned long valuemask;
@@ -85,6 +86,8 @@ createwindow3(win_num, xmin_vp, xmax_vp, ymin_vp, ymax_vp, nerr)
   *nerr = 0;
   ptitle_label = title_label;
 
+  wm_delete_window = XInternAtom(display3, "WM_DELETE_WINDOW", False);
+
 /* Set up boundaries of window */
 
   xul_p = (int) ((float) (scr_width_p3-1) * *xmin_vp);
@@ -210,8 +213,10 @@ createwindow3(win_num, xmin_vp, xmax_vp, ymin_vp, ymax_vp, nerr)
 
 #endif /* USE_X11_DOUBLE_BUFFER */
 
-/* Select events will be accepted by each window */
+/* Select events will be accepted by each window; notify window manager
+   that we will handle window deletions, not it.  */
 
+  XSetWMProtocols(display3, basew3[*win_num].win, &wm_delete_window, 1);
   XSelectInput(display3,basew3[*win_num].win,
 	       (ExposureMask | StructureNotifyMask));
 
diff --git a/src/gd3.x11/dispatcheve3.c b/src/gd3.x11/dispatcheve3.c
index c7fc6f4..fed1e66 100755
--- a/src/gd3.x11/dispatcheve3.c
+++ b/src/gd3.x11/dispatcheve3.c
@@ -161,6 +161,16 @@ dispatchevent3(nerr)
 	break;
 #endif
 
+      /* George Helffrich <george@geology.bristol.ac.uk>
+         If you can, handle window destroy events triggered by window manager
+	 here. These are clicks on the close button on the window frame. I
+	 choose to ignore them and leave the window active -- SAC has no
+	 semantics for closing windows except enddevice.
+
+      case ClientMessage:
+        *nerr = 1;
+        break;
+      */
 
       case ConfigureNotify:
 	if (is_basew) {