Index: tests/parameters.test
===================================================================
diff -u -N -rb6fa800493538a2f179224f7f1717eb70913dd8b -rdc94a1f141b1c6a106d0ee142c9df2743ac82e67
--- tests/parameters.test	(.../parameters.test)	(revision b6fa800493538a2f179224f7f1717eb70913dd8b)
+++ tests/parameters.test	(.../parameters.test)	(revision dc94a1f141b1c6a106d0ee142c9df2743ac82e67)
@@ -104,7 +104,7 @@
   ? {::nsf::is integer 0xy} 0
 
   # built in converter, but not allowed
-  ? {::nsf::is switch 1} {invalid value constraints "switch"}
+  ? {::nsf::is switch 1} {invalid value constraints "switch": invalid parameter type "switch" for argument "value"; type "switch" only allowed for non-positional arguments}
   ? {::nsf::is superclass M} {invalid value constraints "superclass"}
 
   # don't allow convert;