diff --git a/doc/release_notes.rst b/doc/release_notes.rst
index f5048ad0..7e7fab1f 100644
--- a/doc/release_notes.rst
+++ b/doc/release_notes.rst
@@ -10,7 +10,7 @@ Release Notes
 Upcoming Release
 ================
 
-* new features
+* The solver configuration in `config.default.yaml` are now modularized. To change the set of solver options, change to value in `solving`: `solver`: `options` to one of the keys `solving`: `solver_options`. 
 
 
 PyPSA-Eur 0.7.0 (16th February 2023)