Clarified Changelog for fix #602
diff --git a/ChangeLog b/ChangeLog
index d64ce68..49fdbcc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -18,7 +18,7 @@
      builds where the configuration POLARSSL_PEM_WRITE_C is not defined. Found
      by inestlerode. #559.
    * Fix documentation and implementation missmatch for function arguments of
-     mbedtls_gcm_finish(). Found by cmiatpaar.
+     mbedtls_gcm_finish(). Found by cmiatpaar. #602
 
 = mbed TLS 1.3.17 branch 2016-06-28