diff --git a/slurm.changes b/slurm.changes
index d7a12b6..374adc3 100644
--- a/slurm.changes
+++ b/slurm.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Tue May 10 10:26:02 UTC 2022 - Egbert Eich <eich@suse.com>
+
+- Add a comment about the CommunicationParameters=block_null_hash
+  option warning users who migrate - just in case.
+
 -------------------------------------------------------------------
 Fri May  6 09:33:34 UTC 2022 - Christian Goll <cgoll@suse.com>
 
diff --git a/slurm.spec b/slurm.spec
index a44e830..a4c9217 100644
--- a/slurm.spec
+++ b/slurm.spec
@@ -651,6 +651,8 @@ sed -i -e '/^ControlMachine=/i# Ordered List of Control Nodes' \
     -e '/.*BackupAddr=.*/d'  %{buildroot}/%{_sysconfdir}/%{pname}/slurm.conf
 cat >>%{buildroot}/%{_sysconfdir}/%{pname}/slurm.conf <<EOF
 # Potential exploit mitigation CVE-2022-29500
+# When upgrading from a version without this fix
+# enable only after all daemons have been upgraded
 CommunicationParameters=block_null_hash
 # SUSE default configuration
 PropagateResourceLimitsExcept=MEMLOCK