diff --git a/ChangeLog b/ChangeLog
index 2275d6e60..1ed73d9a0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -31,6 +31,9 @@ Bugfix
      a contribution from Tobias Tangemann. #541
    * Fixed cert_app sample program for debug output and for use when no root
      certificates are provided.
+   * Fixed sample application 'programs/pkey/gen_key.c' for builds where the
+     configuration MBEDTLS_PEM_WRITE_C is not defined. Found by inestlerode.
+     #559.
    * Fixed default threading implementation to avoid accidental double
      initialisations and double frees.
    * Fix mbedtls_x509_get_sig() to update the ASN1 type in the mbedtls_x509_buf