diff --git a/data/freedesktop-dbus-interfaces.xml b/data/freedesktop-dbus-interfaces.xml
index da37ca0e00..d648205cff 100644
--- a/data/freedesktop-dbus-interfaces.xml
+++ b/data/freedesktop-dbus-interfaces.xml
@@ -31,5 +31,13 @@
       <arg type='s' name='StartupId' direction='in'/>
     </method>
     <property name="OpenLocations" type="as" access="read"/>
+    <!--
+      An extension to the official FileManager1 interface that allows Nautilus
+      to publish a mapping of windows to the locations in each window.
+      This can be used by shell extensions like dash-to-dock/ubuntu-dock to
+      associate special dock icons with windows where the icon's location is
+      open.
+      -->
+    <property name="OpenWindowsWithLocations" type="a{sas}" access="read"/>
   </interface>
 </node>
diff --git a/src/nautilus-application.c b/src/nautilus-application.c
index f38340e240..6584bd7026 100644
--- a/src/nautilus-application.c
+++ b/src/nautilus-application.c
@@ -1400,6 +1400,10 @@ update_dbus_opened_locations (NautilusApplication *self)
     gchar **locations_array;
     NautilusWindow *window;
     GFile *location;
+    const gchar *dbus_object_path = NULL;
+
+    g_autoptr (GVariant) windows_to_locations;
+    GVariantBuilder windows_to_locations_builder;
 
     g_return_if_fail (NAUTILUS_IS_APPLICATION (self));
 
@@ -1412,10 +1416,22 @@ update_dbus_opened_locations (NautilusApplication *self)
         return;
     }
 
+    dbus_object_path = g_application_get_dbus_object_path (G_APPLICATION (self));
+
+    g_return_if_fail (dbus_object_path);
+
+    g_variant_builder_init (&windows_to_locations_builder, G_VARIANT_TYPE ("a{sas}"));
+
     for (l = priv->windows; l != NULL; l = l->next)
     {
+        guint32 id;
+        g_autofree gchar *path = NULL;
+        GVariantBuilder locations_in_window_builder;
+
         window = l->data;
 
+        g_variant_builder_init (&locations_in_window_builder, G_VARIANT_TYPE ("as"));
+
         for (sl = nautilus_window_get_slots (window); sl; sl = sl->next)
         {
             NautilusWindowSlot *slot = sl->data;
@@ -1426,6 +1442,8 @@ update_dbus_opened_locations (NautilusApplication *self)
                 gchar *uri = g_file_get_uri (location);
                 GList *found = g_list_find_custom (locations, uri, (GCompareFunc) g_strcmp0);
 
+                g_variant_builder_add (&locations_in_window_builder, "s", uri);
+
                 if (!found)
                 {
                     locations = g_list_prepend (locations, uri);
@@ -1437,6 +1455,11 @@ update_dbus_opened_locations (NautilusApplication *self)
                 }
             }
         }
+
+        id = gtk_application_window_get_id (GTK_APPLICATION_WINDOW (window));
+        path = g_strdup_printf ("%s/window/%u", dbus_object_path, id);
+        g_variant_builder_add (&windows_to_locations_builder, "{sas}", path, &locations_in_window_builder);
+        g_variant_builder_clear (&locations_in_window_builder);
     }
 
     locations_array = g_new (gchar *, locations_size + 1);
@@ -1452,6 +1475,10 @@ update_dbus_opened_locations (NautilusApplication *self)
     nautilus_freedesktop_dbus_set_open_locations (priv->fdb_manager,
                                                   (const gchar **) locations_array);
 
+    windows_to_locations = g_variant_ref_sink (g_variant_builder_end (&windows_to_locations_builder));
+    nautilus_freedesktop_dbus_set_open_windows_with_locations (priv->fdb_manager,
+                                                               windows_to_locations);
+
     g_free (locations_array);
     g_list_free_full (locations, g_free);
 }
diff --git a/src/nautilus-freedesktop-dbus.c b/src/nautilus-freedesktop-dbus.c
index 554b1bc3d5..408532f8d3 100644
--- a/src/nautilus-freedesktop-dbus.c
+++ b/src/nautilus-freedesktop-dbus.c
@@ -43,6 +43,7 @@ struct _NautilusFreedesktopDBus
     NautilusFreedesktopFileManager1 *skeleton;
 
     GStrv pending_open_locations;
+    GVariant *pending_open_windows_with_locations;
 
     gboolean name_lost;
 };
@@ -173,6 +174,15 @@ bus_acquired_cb (GDBusConnection *conn,
 
         nautilus_freedesktop_dbus_set_open_locations (fdb, (const gchar **) locations);
     }
+
+    if (G_UNLIKELY (fdb->pending_open_windows_with_locations != NULL))
+    {
+        g_autoptr (GVariant) locations = NULL;
+
+        locations = g_steal_pointer (&fdb->pending_open_windows_with_locations);
+
+        nautilus_freedesktop_dbus_set_open_windows_with_locations (fdb, locations);
+    }
 }
 
 static void
@@ -226,6 +236,7 @@ nautilus_freedesktop_dbus_finalize (GObject *object)
     fdb = NAUTILUS_FREEDESKTOP_DBUS (object);
 
     g_clear_pointer (&fdb->pending_open_locations, g_strfreev);
+    g_clear_pointer (&fdb->pending_open_windows_with_locations, g_variant_unref);
 }
 
 static void
@@ -250,6 +261,7 @@ nautilus_freedesktop_dbus_init (NautilusFreedesktopDBus *fdb)
                                     NULL);
     fdb->skeleton = NULL;
     fdb->pending_open_locations = NULL;
+    fdb->pending_open_windows_with_locations = NULL;
     fdb->name_lost = FALSE;
 }
 
@@ -276,6 +288,40 @@ nautilus_freedesktop_dbus_set_open_locations (NautilusFreedesktopDBus  *fdb,
     }
 }
 
+/**
+ * nautilus_freedesktop_dbus_set_open_windows_with_locations:
+ * fdb: The skeleton for the dbus interface
+ * locations: Mapping of windows to locations open in each window
+ *
+ * This allows the application to publish the locations that are open in each window.
+ * It is used by shell extensions like dash-to-dock/ubuntu-dock to match special dock
+ * icons to the windows where the icon's location is open. For example, the Trash or
+ * a removable device.
+ */
+void
+nautilus_freedesktop_dbus_set_open_windows_with_locations (NautilusFreedesktopDBus *fdb,
+                                                           GVariant                *locations)
+{
+    g_return_if_fail (NAUTILUS_IS_FREEDESKTOP_DBUS (fdb));
+
+    if (G_UNLIKELY (fdb->skeleton == NULL))
+    {
+        if (G_LIKELY (fdb->name_lost))
+        {
+            return;
+        }
+
+        g_clear_pointer (&fdb->pending_open_windows_with_locations, g_variant_unref);
+
+        fdb->pending_open_windows_with_locations = g_variant_ref (locations);
+    }
+    else
+    {
+        nautilus_freedesktop_file_manager1_set_open_windows_with_locations (fdb->skeleton,
+                                                                            locations);
+    }
+}
+
 /* Tries to own the org.freedesktop.FileManager1 service name */
 NautilusFreedesktopDBus *
 nautilus_freedesktop_dbus_new (void)
diff --git a/src/nautilus-freedesktop-dbus.h b/src/nautilus-freedesktop-dbus.h
index 57dfef7189..6c54be6c4a 100644
--- a/src/nautilus-freedesktop-dbus.h
+++ b/src/nautilus-freedesktop-dbus.h
@@ -45,3 +45,5 @@ GType nautilus_freedesktop_dbus_get_type (void);
 NautilusFreedesktopDBus * nautilus_freedesktop_dbus_new (void);
 
 void nautilus_freedesktop_dbus_set_open_locations (NautilusFreedesktopDBus *fdb, const gchar **locations);
+
+void nautilus_freedesktop_dbus_set_open_windows_with_locations (NautilusFreedesktopDBus *fdb, GVariant *locations);