diff --git a/global-functions.rsc b/global-functions.rsc
index 1d5f55c3..6ac2ba45 100644
--- a/global-functions.rsc
+++ b/global-functions.rsc
@@ -1043,6 +1043,7 @@
 
 # return an IPv6 netmask for CIDR
 :set NetMask6 do={
+  :local FuncName $0;
   :local CIDR [ :tostr $1 ];
 
   :global IfThenElse;