Index: generic/nsf.c
===================================================================
diff -u -N -r4d5e72a9e5c7269822ecf79201f95bdb4a165d43 -r52340117d4ce34fdfd10a838b803f2e49d525542
--- generic/nsf.c	(.../nsf.c)	(revision 4d5e72a9e5c7269822ecf79201f95bdb4a165d43)
+++ generic/nsf.c	(.../nsf.c)	(revision 52340117d4ce34fdfd10a838b803f2e49d525542)
@@ -34608,6 +34608,11 @@
   rst->NsfClassesNS =
     Tcl_CreateNamespace(interp, "::nsf::classes", NULL,
                         (Tcl_NamespaceDeleteProc *)NULL);
+
+#if !defined(PRE86)
+  ((Namespace *)rst->NsfClassesNS)->flags |= NS_SUPPRESS_COMPILATION;
+#endif
+
   MEM_COUNT_ALLOC("TclNamespace", rst->NsfClassesNS);
 
   /*