diff --git a/documentation/migration-guides/migration-5.2.rst b/documentation/migration-guides/migration-5.2.rst
index e9de6910e1..a60e3e9a80 100644
--- a/documentation/migration-guides/migration-5.2.rst
+++ b/documentation/migration-guides/migration-5.2.rst
@@ -94,6 +94,17 @@ systemd changes
    not for socket files).
    Now all service files must be explicitly added to :term:`FILES`.
 
+Multiconfig changes
+~~~~~~~~~~~~~~~~~~~
+
+The value of ``BB_CURRENT_MC`` was changed from ``default`` to an empty string
+for the default multiconfig configuration to avoid needing to map the values
+within BitBake. This was already not happening in some cases so this fixes
+some obscure bugs.
+
+Any logic based on ``BB_CURRENT_MC`` equalling to ``default`` by default should
+be changed to be equal to an empty string.
+
 Recipe changes
 ~~~~~~~~~~~~~~