diff --git a/manual/release-notes.rst b/manual/release-notes.rst
index 39ebcd7..2b6b6de 100644
--- a/manual/release-notes.rst
+++ b/manual/release-notes.rst
@@ -13,7 +13,12 @@ more detail.
 
 .. x.y.z: not yet released
 
-12.1.0: not yet released
+12.1.0: April 6, 2025
+  - Upcoming C++ Version Change
+
+    - This is expected to be the last minor release of qpdf to work
+      with C++-17. We will be switching to C++-20 for 12.2.0.
+
   - Bug fixes
 
     - In ``QPDF::isLinearized`` return false if the first object in the file is