diff --git a/doc/releases/migration-guide-4.0.rst b/doc/releases/migration-guide-4.0.rst
index 3581625f830..e6a5ea98c0a 100644
--- a/doc/releases/migration-guide-4.0.rst
+++ b/doc/releases/migration-guide-4.0.rst
@@ -243,6 +243,18 @@ Bluetooth Classic
 Bluetooth Host
 ==============
 
+:c:func:`bt_l2cap_ecred_chan_reconfigure`
+-----------------------------------------
+
+:c:func:`bt_l2cap_ecred_chan_reconfigure` now expects the ``mps`` parameter
+explicitly. To upgrade without change in behavior, perform the following
+substitution:
+
+.. code-block:: diff
+   -bt_l2cap_ecred_chan_reconfigure(chan, mtu);
+   +uint16_t mps = MIN(mtu + BT_L2CAP_SDU_HDR_SIZE, BT_L2CAP_RX_MTU);
+   +bt_l2cap_ecred_chan_reconfigure(chan, mtu, mps);
+
 Bluetooth Crypto
 ================
 
diff --git a/doc/releases/release-notes-4.0.rst b/doc/releases/release-notes-4.0.rst
index 76eaa3ac62f..b0f8ba6da3e 100644
--- a/doc/releases/release-notes-4.0.rst
+++ b/doc/releases/release-notes-4.0.rst
@@ -105,6 +105,9 @@ Bluetooth
     :c:func:`bt_conn_le_create` and :c:func:`bt_conn_le_create_synced` return an error if the
     connection pointer passed as an argument is not NULL.
 
+  * Added parameter ``mps`` to :c:func:`bt_l2cap_ecred_chan_reconfigure`. See migration guide for
+    more details.
+
 * HCI Drivers
 
 Boards & SoC Support