diff --git a/migrate2rocky/README.md b/migrate2rocky/README.md
index 07037c4..3064d87 100644
--- a/migrate2rocky/README.md
+++ b/migrate2rocky/README.md
@@ -16,15 +16,22 @@ Running this script will convert an existing CentOS 8 system to Rocky Linux 8.
 
 ### Known Issues
 
-#### Katello clashes
+#### Custom replacements of default repositories
 
-Katello installs its own repositories via subscription-manager that are meant to
-replace the ones from CentOS, but it does not remove, or even disable, the
-corresponding CentOS repositories.  This would cause issues to a normal running
-system, but it is especially problematic for migrate2rocky as it means that
-migrate2rocky cannot properly determine which repositories to remove and
-attempting to run migrate2rocky on a katello will likely result in a corrupted
-system.
+This script expects the **original repository configuration being present, as well
+as enabled** (i.e. for CentOS the `baseos` repo configuration in the
+`/etc/yum.repos.d/CentOS-Linux-BaseOS.repo` file has to be present and enabled).
+Also make sure that there are **no other repositories** which could interfere with the
+original configuration.
+
+Any distribution that has had its core repositories altered, removed, duplicated
+or overridden may cause migrate2rocky to break or corrupt the system when run.
+Any attempt to migrate such systems, even after reversing the changes made by such
+software, is not supported in any way. In all cases you should backup your system
+before using migrate2rocky and USE AT YOUR OWN RISK.
+
+This especially happens on systems configured with a centralized package management
+like Katello (RedHat Satellite 6) or Uyuni (RedHat Satellite 5, SUSE Manager).
 
 #### RHEL migrations show error messages during conversion
 
diff --git a/migrate2rocky/migrate2rocky.sh b/migrate2rocky/migrate2rocky.sh
index 85f36dd..51cc3ca 100644
--- a/migrate2rocky/migrate2rocky.sh
+++ b/migrate2rocky/migrate2rocky.sh
@@ -191,7 +191,10 @@ exit_clean () {
 
 pre_check () {
     if [[ -e /etc/rhsm/ca/katello-server-ca.pem ]]; then
-	exit_message "Migration from Katello-modified systems is not supported by migrate2rocky."
+	    exit_message "Migration from Katello-modified systems is not supported by migrate2rocky. See the README file for details."
+    fi
+    if [[ -e /etc/salt/minion.d/susemanager.conf ]]; then
+        exit_message "Migration from Uyuni/SUSE Manager-modified systems is not supported by migrate2rocky. See the README file for details."
     fi
 }