diff --git a/threshold b/threshold
index f38e9e7..244423c 100755
--- a/threshold
+++ b/threshold
@@ -671,9 +671,10 @@ class Helper(object):
                         toUnset = True
 
                     if spl[2] == "authtype":
-                        if not spl[3] in ["sp", "ns"]:
-                            failure("Authtype must be sp or ns, not %s" % spl[3])
-                            return
+                        if not toUnset:
+                            if not spl[3] in ["sp", "ns"]:
+                                failure("Authtype must be sp or ns, not %s" % spl[3])
+                                return
                     if spl[2] == "enabled":
                         failure("Use the enable and disable commands to manage this")
                         return