diff --git a/parsers/survex.py b/parsers/survex.py
index ed70a4b..0c108ac 100644
--- a/parsers/survex.py
+++ b/parsers/survex.py
@@ -206,7 +206,7 @@ def RecursiveLoad(survexblock, survexfile, fin, textlines):
             survexblock.MakeSurvexStation(line.split()[0])
 
         else:
-            if not cmd in [ "sd", "include", "units", "entrance", "data", "flags", "title", "export", "instrument", "calibrate", "set", "infer", "alias" ]:
+            if not cmd in [ "sd", "include", "units", "entrance", "data", "flags", "title", "export", "instrument", "calibrate", "set", "infer", "alias", "ref" ]:
                 print ("Unrecognised command in line:", cmd, line, survexblock)