diff --git a/src/popupwin.c b/src/popupwin.c
index e1fc0a7..b6bb593 100644
--- a/src/popupwin.c
+++ b/src/popupwin.c
@@ -2140,4 +2140,50 @@
     }
 }
 
+/*
+ * Mark references in callbacks of one popup window.
+ */
+    static int
+set_ref_in_one_popup(win_T *wp, int copyID)
+{
+    int		abort = FALSE;
+    typval_T	tv;
+
+    if (wp->w_close_cb.cb_partial != NULL)
+    {
+	tv.v_type = VAR_PARTIAL;
+	tv.vval.v_partial = wp->w_close_cb.cb_partial;
+	abort = abort || set_ref_in_item(&tv, copyID, NULL, NULL);
+    }
+    if (wp->w_filter_cb.cb_partial != NULL)
+    {
+	tv.v_type = VAR_PARTIAL;
+	tv.vval.v_partial = wp->w_filter_cb.cb_partial;
+	abort = abort || set_ref_in_item(&tv, copyID, NULL, NULL);
+    }
+    return abort;
+}
+
+/*
+ * Set reference in callbacks of popup windows.
+ */
+    int
+set_ref_in_popups(int copyID)
+{
+    int		abort = FALSE;
+    win_T	*wp;
+    tabpage_T	*tp;
+
+    for (wp = first_popupwin; !abort && wp != NULL; wp = wp->w_next)
+	abort = abort || set_ref_in_one_popup(wp, copyID);
+
+    FOR_ALL_TABPAGES(tp)
+    {
+	for (wp = tp->tp_first_popupwin; !abort && wp != NULL; wp = wp->w_next)
+	    abort = abort || set_ref_in_one_popup(wp, copyID);
+	if (abort)
+	    break;
+    }
+    return abort;
+}
 #endif // FEAT_TEXT_PROP