diff --git a/ChangeLog.d/fix-session-copy-bug.txt b/ChangeLog.d/fix-session-copy-bug.txt
new file mode 100644
index 0000000..46e3d8e
--- /dev/null
+++ b/ChangeLog.d/fix-session-copy-bug.txt
@@ -0,0 +1,6 @@
+Bugfix
+   * Fix a double-free that happened after mbedtls_ssl_set_session() or
+     mbedtls_ssl_get_session() failed with MBEDTLS_ERR_SSL_ALLOC_FAILED
+     (out of memory). After that, calling mbedtls_ssl_session_free()
+     and mbedtls_ssl_free() would cause an internal session buffer to
+     be free()'d twice.