diff --git a/internal b/internal
index 432179d..6898173 100755
--- a/internal
+++ b/internal
@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 'Command line program to exercise/test/debug the _internal command.'
 # Mark Blakeney, Oct 2019
-import sys, importlib, argparse
+import sys, importlib.util, importlib.machinery, argparse
 from pathlib import Path
 
 CMD = '_internal'