diff --git a/peps/pep-0007.rst b/peps/pep-0007.rst
index fc86f045067..3b32afc6390 100644
--- a/peps/pep-0007.rst
+++ b/peps/pep-0007.rst
@@ -35,6 +35,11 @@ C dialect
   <https://en.wikipedia.org/wiki/C11_%28C_standard_revision%29#Optional_features>`_.
   The public C API should be compatible with C++.
 
+* Python 3.12 provided best effort support for the
+  ``-Werror=declaration-after-statement`` compiler flag (forbid mixed
+  declarations and code) for the C API. It is no longer the case in
+  Python 3.13: this flag should not be used with the Python C API.
+
 * Python 3.6 to 3.10 use C89 with several select C99 features:
 
   - Standard integer types in ``<stdint.h>`` and ``<inttypes.h>``. We