diff --git a/hooks/upgrade-charm b/hooks/upgrade-charm
index 14948004..71a85b0a 100755
--- a/hooks/upgrade-charm
+++ b/hooks/upgrade-charm
@@ -1,4 +1,9 @@
 #!/bin/bash -e
-# Re-install dependencies to deal with py2->py3 switch for charm
 
+# Wrapper to ensure that old python bytecode isn't hanging around
+# after we upgrade the charm with newer libraries
+find . -iname '*.pyc' -delete
+find . -name '__pycache__' -prune -exec rm -rf "{}" \;
+
+# Re-install dependencies to deal with py2->py3 switch for charm
 ./hooks/install_deps