diff --git a/NOTES.md b/NOTES.md
index a1b92a6..7aa1297 100644
--- a/NOTES.md
+++ b/NOTES.md
@@ -4,6 +4,9 @@ cf. [Bash Reference Manual](https://www.gnu.org/savannah-checkouts/gnu/bash/manu
 
 Comparative testing with bash should be done with bash --norc --posix.
 
+## Ideas for testing
+* use prysk or shellspec with shell=./minishell
+
 ## Shell Operation
 
 cf. 3.1.1 Shell Operation