diff --git a/ChangeLog b/ChangeLog
index b661bee820..9a77163f06 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2004-11-29  Sven Neumann  <sven@gimp.org>
+
+	* libgimpwidgets/gimppreview.c (gimp_preview_toggle_callback):
+	change the "update" property and notify listeners (in particular
+	GimpDrawablePreview) before invalidating the preview. Plug-ins
+	might (needlessly) look at the property to decide whether they
+	need to redraw. Fixes bug #159816.
+
+	* plug-ins/common/unsharp.c (preview_update): no need to look at
+	the value of the "Preview" toggle. GimpPreview takes care this.
+
 2004-11-29  DindinX  <dindinx@gimp.org>
 
 	* plug-ins/gfig/gfig-dialog.c: issue a repaint after the
diff --git a/libgimpwidgets/gimppreview.c b/libgimpwidgets/gimppreview.c
index fb0b926520..6fe7afabd9 100644
--- a/libgimpwidgets/gimppreview.c
+++ b/libgimpwidgets/gimppreview.c
@@ -399,6 +399,8 @@ gimp_preview_toggle_callback (GtkWidget   *toggle,
     {
       preview->update_preview = TRUE;
 
+      g_object_notify (G_OBJECT (preview), "update");
+
       if (preview->timeout_id)
         g_source_remove (preview->timeout_id);
 
@@ -408,10 +410,10 @@ gimp_preview_toggle_callback (GtkWidget   *toggle,
     {
       preview->update_preview = FALSE;
 
+      g_object_notify (G_OBJECT (preview), "update");
+
       gimp_preview_draw (preview);
     }
-
-  g_object_notify (G_OBJECT (preview), "update");
 }
 
 static void
diff --git a/plug-ins/common/unsharp.c b/plug-ins/common/unsharp.c
index acfc9c9516..fe1dace8b0 100644
--- a/plug-ins/common/unsharp.c
+++ b/plug-ins/common/unsharp.c
@@ -758,9 +758,6 @@ preview_update (GimpPreview *preview)
 
   GimpPixelRgn  srcPR, destPR;        /* Pixel regions */
 
-  if (!unsharp_params.update_preview)
-    return;
-
   drawable =
     gimp_drawable_preview_get_drawable (GIMP_DRAWABLE_PREVIEW (preview));