diff --git a/src/xfns.c b/src/xfns.c
index ede53262f5f..2ab185a3c2d 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -4637,6 +4637,7 @@ x_create_tip_frame (dpyinfo, parms, text)
 
   check_x ();
 
+  parms = Fcopy_alist (parms);
 
 #ifdef MULTI_KBOARD
   kb = dpyinfo->kboard;