diff --git a/doc/appendix-release-notes.sgml b/doc/appendix-release-notes.sgml
index aa8ce45f..78ae55c7 100644
--- a/doc/appendix-release-notes.sgml
+++ b/doc/appendix-release-notes.sgml
@@ -30,6 +30,15 @@
       for more details.
     </para>
 
+    <note>
+      <para>
+        It is not possible to perform a switchover where the demotion candidate is
+        running &repmgr; 4.0.2 or lower; all nodes should be upgraded to the latest version (4.0.4).
+        This is due to additional checks introduced in 4.0.3 which require the presence of
+        4.0.3 or later versions on all nodes.
+      </para>
+    </note>
+
     <sect2>
       <title>Usability enhancements</title>
 
@@ -144,6 +153,14 @@
       This release can be installed as a simple package upgrade from repmgr 4.0 ~ 4.0.2;
       repmgrd (if running) should be restarted.
     </para>
+    <note>
+      <para>
+        It is not possible to perform a switchover where the demotion candidate is
+        running &repmgr; 4.0.2 or lower; all nodes should be upgraded to 4.0.3. This is due
+        to additional checks introduced in 4.0.3 which require the presence of
+        4.0.3 or later versions on all nodes.
+      </para>
+    </note>
     <sect2>
       <title>Usability enhancements</title>