diff --git a/c/xlib/display.c b/c/xlib/display.c
index 70eaec7..703a358 100644
--- a/c/xlib/display.c
+++ b/c/xlib/display.c
@@ -2,6 +2,8 @@
 #include "scheme48.h"
 #include <sys/time.h>
 
+s48_value internal_after_function_binding = S48_FALSE;
+
 // Open_Display(name) name should be a string or S48_FALSE (=> Null)
 s48_value scx_Open_Display (s48_value name) {
   char* cname = (char*)0;
@@ -18,6 +20,22 @@ s48_value scx_Close_Display(s48_value Xdisplay) {
   return S48_UNSPECIFIC;
 }
 
+
+// After-Function routines
+static X_After_Function(Display* d) {
+  s48_call_scheme(S48_SHARED_BINDING_REF(internal_after_function_binding),
+		  1, SCX_ENTER_DISPLAY(d));
+}
+
+s48_value scx_Set_After_Function(s48_value Xdisplay, s48_value active) {
+  if (S48_FALSE_P(active))
+    (void)XSetAfterFunction(SCX_EXTRACT_DISPLAY(Xdisplay),
+			    (int (*)())0);
+  else
+    (void)XSetAfterFunction(SCX_EXTRACT_DISPLAY(Xdisplay),
+			    X_After_Function);
+}
+
 // This function returns the file destriptor of the message-channel.
 s48_value scx_Display_Message_fd(s48_value Xdisplay) {
   int fd = ConnectionNumber(SCX_EXTRACT_DISPLAY(Xdisplay));
@@ -211,6 +229,11 @@ s48_value scx_List_Pixmap_Formats (s48_value Xdisplay) {
 }
 
 void scx_init_display(void) {
+  S48_GC_PROTECT_GLOBAL(internal_after_function_binding);
+  internal_after_function_binding = 
+    s48_get_imported_binding("internal-after-function");
+
+  S48_EXPORT_FUNCTION(scx_Set_After_Function);
   S48_EXPORT_FUNCTION(scx_Open_Display);
   S48_EXPORT_FUNCTION(scx_Close_Display);
   S48_EXPORT_FUNCTION(scx_Display_Message_fd);
diff --git a/scheme/xlib/display-type.scm b/scheme/xlib/display-type.scm
index d987e96..0207990 100644
--- a/scheme/xlib/display-type.scm
+++ b/scheme/xlib/display-type.scm
@@ -6,11 +6,28 @@
   (after-function display-after-function real-display-set-after-function!) 
   (Xdisplay display-Xdisplay display-set-Xdisplay!))
 
+;; the real AfterFunction registered at the xlib is either none or the
+;; c-function X_After_Function, which then calls
+;; internal-after-function.
+
 (define (display-set-after-function! display proc)
   (let ((old (display-after-function display)))
     (real-display-set-after-function! display proc)
+    (%set-after-function (display-Xdisplay display) proc)
     old))
 
+(import-lambda-definition %set-after-function (Xdisplay active?)
+  "scx_Set_After_Function")
+
+(define (internal-after-function Xdisplay)
+  (let ((display (make-display Xdisplay #f)))
+    (if (display-after-function display)
+	((display-after-function display) display))))
+
+(define-exported-binding "internal-after-function" internal-after-function)
+
+;; the constructor
+
 (define (make-display Xdisplay finalize?)
   (let ((maybe-display (display-list-find Xdisplay)))
     (if maybe-display