diff --git a/src/secmod_eddsa.ml b/src/secmod_eddsa.ml
index 481a2762..71b28d06 100644
--- a/src/secmod_eddsa.ml
+++ b/src/secmod_eddsa.ml
@@ -1,5 +1,6 @@
 (* TODO
    ! use lock
+   ! Scanf not thread-safe, replace with Angstrom(?)
    schedule tasks
    sign: check timestamps before signing *)
 (* IMPROVE