diff --git a/hardware/errata.md b/hardware/errata.md
index 3dde748..5e64dab 100644
--- a/hardware/errata.md
+++ b/hardware/errata.md
@@ -34,3 +34,4 @@ Rev 1
 * enlarge holes to fit M3 screws comfortably
 * add 15M (TBC) resistor between A and FIL-
 * power U200 from a small negative voltage instead of GND
+* review choice of filament flyback output diode