diff --git a/interface-definitions/firewall.xml.in b/interface-definitions/firewall.xml.in
index 24e63c5ecc..32211ce3bf 100644
--- a/interface-definitions/firewall.xml.in
+++ b/interface-definitions/firewall.xml.in
@@ -20,8 +20,13 @@
             <properties>
               <help>Interfaces to use this flowtable</help>
               <completionHelp>
-                <script>${vyos_completion_dir}/list_interfaces</script>
+                <path>interfaces ethernet</path>
+                <path>interfaces loopback</path>
               </completionHelp>
+               <constraint>
+                <regex>^(eth\d+|lo)$</regex>
+              </constraint>
+              <constraintErrorMessage>Only ethernet and loopback interfaces are allowed in flowtables</constraintErrorMessage>
               <multi/>
             </properties>
           </leafNode>
diff --git a/smoketest/scripts/cli/test_firewall.py b/smoketest/scripts/cli/test_firewall.py
index c475627142..3f01e43ef2 100755
--- a/smoketest/scripts/cli/test_firewall.py
+++ b/smoketest/scripts/cli/test_firewall.py
@@ -802,7 +802,7 @@ def test_zone_basic(self):
 
     def test_flow_offload(self):
         self.cli_set(['interfaces', 'ethernet', 'eth0', 'vif', '10'])
-        self.cli_set(['firewall', 'flowtable', 'smoketest', 'interface', 'eth0.10'])
+        self.cli_set(['firewall', 'flowtable', 'smoketest', 'interface', 'eth0'])
         self.cli_set(['firewall', 'flowtable', 'smoketest', 'offload', 'hardware'])
 
         # QEMU virtual NIC does not support hw-tc-offload
@@ -828,7 +828,7 @@ def test_flow_offload(self):
         nftables_search = [
             ['flowtable VYOS_FLOWTABLE_smoketest'],
             ['hook ingress priority filter'],
-            ['devices = { eth0.10 }'],
+            ['devices = { eth0 }'],
             ['ct state { established, related }', 'meta l4proto { tcp, udp }', 'flow add @VYOS_FLOWTABLE_smoketest'],
         ]
 
diff --git a/src/migration-scripts/firewall/15-to-16 b/src/migration-scripts/firewall/15-to-16
new file mode 100755
index 0000000000..ee4f2cb8ef
--- /dev/null
+++ b/src/migration-scripts/firewall/15-to-16
@@ -0,0 +1,67 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2022-2024 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# T6265: allow only ethernet and loopback interface on firewall flowtables
+# If non ethernet|lo interface found in flowtables, remove it
+# If after removing flowtable is empty, add lo interface in order to keep it
+
+from sys import argv
+from sys import exit
+
+from vyos.configtree import ConfigTree
+
+if len(argv) < 2:
+    print("Must specify file name!")
+    exit(1)
+
+file_name = argv[1]
+
+with open(file_name, 'r') as f:
+    config_file = f.read()
+
+config = ConfigTree(config_file)
+base = ['firewall', 'flowtable']
+
+if not config.exists(base):
+    # Nothing to do
+    exit(0)
+
+valid_str = ['eth','lo']
+invalid_arguments = ['.']
+
+for ft in config.list_nodes(base):
+    interfaces = config.return_values(base + [ft, 'interface'])
+    # Remove all node, and only add what is allowed
+    config.delete(base + [ft, 'interface'])
+    for iface in interfaces:
+        for aux in valid_str:
+            if aux in iface:
+                ## We may need to re-add it
+                for inv_arg in invalid_arguments:
+                    if inv_arg not in iface:
+                        # We need to re-add it
+                        config.set(base + [ft, 'interface'], value=iface, replace=False)
+
+    # Now we need to check that >ft interface> is not empty
+    if 'interface' not in config.list_nodes(base + [ft]):
+        config.set(base + [ft, 'interface'], value='lo')
+
+try:
+    with open(file_name, 'w') as f:
+        f.write(config.to_string())
+except OSError as e:
+    print("Failed to save the modified config: {}".format(e))
+    exit(1)
\ No newline at end of file