diff --git a/README.md b/README.md
index 36d13a1..0d15ce3 100644
--- a/README.md
+++ b/README.md
@@ -106,4 +106,5 @@ Make the prototype.
     [ ] move USB 0.5-1mm more out
     [ ] DIP SW PADS too narrow
     [x] AUDIO jack footprint fits
+    [ ] AUDIO jack pin 4 not connected
     [ ] BTN footprint too small