diff --git a/scripts/install/manager/install_user_manager.sh b/scripts/install/manager/install_user_manager.sh
index 577f236..e1ee862 100755
--- a/scripts/install/manager/install_user_manager.sh
+++ b/scripts/install/manager/install_user_manager.sh
@@ -46,7 +46,12 @@ installDockerManagerUser()
                 local result=$(source ~/.bashrc)
                 checkSuccess "Reloading .bashrc"
 
-local result=$(sudo bash -c "cat >> $sshd_config <<EOL
+                # Marker-guard the append (matching the rootless .bashrc pattern)
+                # so a re-run or a user delete+recreate can't duplicate the block.
+                if sudo grep -q "### LibrePortal Manager User Start" "$sshd_config"; then
+                    isNotice "Manager-user SSH server config already present — skipping."
+                else
+                    local result=$(sudo bash -c "cat >> $sshd_config <<EOL
 
 ### LibrePortal Manager User Start
 Match User $CFG_DOCKER_MANAGER_USER
@@ -58,12 +63,12 @@ Match User $CFG_DOCKER_MANAGER_USER
     PasswordAuthentication yes
 ### LibrePortal Manager User End
 EOL")
+                    checkSuccess "Updating SSH Server Configuration for the Manager User."
 
-                checkSuccess "Updating SSH Server Configuration for the Manager User."
-
-                # Reload SSH Service
-                local result=$(sudo service ssh reload)
-                checkSuccess "Reloading SSH Service"
+                    # Reload SSH Service
+                    local result=$(sudo service ssh reload)
+                    checkSuccess "Reloading SSH Service"
+                fi
 
                 isSuccessful "User '$CFG_DOCKER_MANAGER_USER' with restricted SFTP access to '/home/$CFG_DOCKER_MANAGER_USER' has been set up."
             fi