diff --git a/config/vlan.py b/config/vlan.py
index 7206868db7..fd70b027cb 100644
--- a/config/vlan.py
+++ b/config/vlan.py
@@ -176,21 +176,21 @@ def del_vlan(db, vid, multiple, no_restart_dhcp_relay):
                
     vlans = db.cfgdb.get_keys('VLAN')
     if not vlans:
-        docker_exec_cmd = "docker exec -i swss {}"
-        _, rc = clicommon.run_command(docker_exec_cmd.format("supervisorctl status ndppd"), ignore_error=True, return_cmd=True)
+        docker_exec_cmd = ['docker', 'exec', '-i', 'swss']
+        _, rc = clicommon.run_command(docker_exec_cmd + ['supervisorctl', 'status', 'ndppd'], ignore_error=True, return_cmd=True)
         if rc == 0:
             click.echo("No VLANs remaining, stopping ndppd service")
-            clicommon.run_command(docker_exec_cmd.format("supervisorctl stop ndppd"), ignore_error=True, return_cmd=True)
-            clicommon.run_command(docker_exec_cmd.format("rm -f /etc/supervisor/conf.d/ndppd.conf"), ignore_error=True, return_cmd=True)
-            clicommon.run_command(docker_exec_cmd.format("supervisorctl update"), return_cmd=True)
+            clicommon.run_command(docker_exec_cmd + ['supervisorctl', 'stop', 'ndppd'], ignore_error=True, return_cmd=True)
+            clicommon.run_command(docker_exec_cmd + ['rm', '-f', '/etc/supervisor/conf.d/ndppd.conf'], ignore_error=True, return_cmd=True)
+            clicommon.run_command(docker_exec_cmd + ['supervisorctl', 'update'], return_cmd=True)
                 
 
 def restart_ndppd():
     verify_swss_running_cmd = ['docker', 'container', 'inspect', '-f', '{{.State.Status}}', 'swss']
     docker_exec_cmd = ['docker', 'exec', '-i', 'swss']
     ndppd_config_gen_cmd = ['sonic-cfggen', '-d', '-t', '/usr/share/sonic/templates/ndppd.conf.j2,/etc/ndppd.conf']
-    ndppd_restart_cmd =['supervisorctl', 'restart', 'ndppd']
-    ndppd_status_cmd= ["supervisorctl", "status", "ndppd"]
+    ndppd_restart_cmd = ['supervisorctl', 'restart', 'ndppd']
+    ndppd_status_cmd = ["supervisorctl", "status", "ndppd"]
     ndppd_conf_copy_cmd = ['cp', '/usr/share/sonic/templates/ndppd.conf', '/etc/supervisor/conf.d/']
     supervisor_update_cmd = ['supervisorctl', 'update']
 
diff --git a/tests/vlan_test.py b/tests/vlan_test.py
index e00d3c40a8..456bb5dd11 100644
--- a/tests/vlan_test.py
+++ b/tests/vlan_test.py
@@ -630,10 +630,10 @@ def test_config_vlan_del_last_vlan(self):
             print(result.exit_code)
             print(result.output)
             mock_run_command.assert_has_calls([
-                mock.call("docker exec -i swss supervisorctl status ndppd", ignore_error=True, return_cmd=True),
-                mock.call("docker exec -i swss supervisorctl stop ndppd", ignore_error=True, return_cmd=True),
-                mock.call("docker exec -i swss rm -f /etc/supervisor/conf.d/ndppd.conf", ignore_error=True, return_cmd=True),
-                mock.call("docker exec -i swss supervisorctl update", return_cmd=True)
+                mock.call(['docker', 'exec', '-i', 'swss', 'supervisorctl', 'status', 'ndppd'], ignore_error=True, return_cmd=True),
+                mock.call(['docker', 'exec', '-i', 'swss', 'supervisorctl', 'stop', 'ndppd'], ignore_error=True, return_cmd=True),
+                mock.call(['docker', 'exec', '-i', 'swss', 'rm', '-f', '/etc/supervisor/conf.d/ndppd.conf'], ignore_error=True, return_cmd=True),
+                mock.call(['docker', 'exec', '-i', 'swss', 'supervisorctl', 'update'], return_cmd=True)
             ])
             assert result.exit_code == 0