diff --git a/prism/NOTES-SIM b/prism/NOTES-SIM
index 7aea91ef..76e06d0d 100644
--- a/prism/NOTES-SIM
+++ b/prism/NOTES-SIM
@@ -14,5 +14,6 @@ TEST CASES
 
 DTMC with local nondet and actions (~/prism-models/dave-test.nm)
 
+GUI transition box: "true" updates don't display correctly