diff --git a/CHANGES b/CHANGES
index b8d187604af381eedbd7852c7a6c8e169ff5d314..0902e037ceb709604ccba8983d9ab5507ad6f070 100644
--- a/CHANGES
+++ b/CHANGES
@@ -7,6 +7,10 @@
   *) New function "CRYPTO_num_locks" that returns CRYPTO_NUM_LOCKS.
      Whoever hopes to achieve shared-library compatibility across versions
      must use this, not the compile-time macro.
+     (Exercise 0.9.4: Which is the minimum library version required by
+     such programs?)
+     Note: All this applies only to multi-threaded programs, others don't
+     need locks.
      [Bodo Moeller]
 
   *) Add missing case to s3_clnt.c state machine -- one of the new SSL tests