Update ChangeLog for recent external bugfix
diff --git a/ChangeLog b/ChangeLog
index 160c0fb..18876e5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -127,6 +127,8 @@
      ciphersuite/certificate.
 
 Bugfix
+   * Fix bug in entropy.c when THREADING_C is also enabled that caused
+     entropy_free() to crash (found and fixed by ptahpeteh).
    * Stack buffer overflow if ctr_drbg_update() is called with too large
      add_len (found by Jean-Philippe Aumasson) (not triggerable remotely).
    * Possible buffer overflow of length at most POLARSSL_MEMORY_ALIGN_MULTIPLE