diff --git a/ChangeLog b/ChangeLog
index 01c916a..392e747 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -37,6 +37,8 @@
      Nick Wilson on issue #355
    * In test_suite_pk, pass valid parameters when testing for hash length
      overflow. #1179
+   * Fix memory allocation corner cases in memory_buffer_alloc.c module. Found
+     by Guido Vranken. #639
 
 Changes
    * Clarified the documentation of mbedtls_ssl_setup.