diff --git a/ansible/roles/neutron/templates/linuxbridge_agent.ini.j2 b/ansible/roles/neutron/templates/linuxbridge_agent.ini.j2
index b952037361..b2f2d8daed 100644
--- a/ansible/roles/neutron/templates/linuxbridge_agent.ini.j2
+++ b/ansible/roles/neutron/templates/linuxbridge_agent.ini.j2
@@ -6,7 +6,7 @@ extensions = {{ neutron_agent_extensions|map(attribute='name')|join(',') }}
 [linux_bridge]
 physical_interface_mappings = physnet1:{{ neutron_external_interface }}
 
-[security_group]
+[securitygroup]
 firewall_driver = neutron.agent.linux.iptables_firewall.IptablesFirewallDriver
 
 [vxlan]
diff --git a/doc/source/reference/networking/neutron.rst b/doc/source/reference/networking/neutron.rst
index 1760f349c8..e00a9b3d3b 100644
--- a/doc/source/reference/networking/neutron.rst
+++ b/doc/source/reference/networking/neutron.rst
@@ -57,7 +57,7 @@ to using the native OVS firewall driver by employing a configuration override
 
 .. code-block:: ini
 
-   [security_group]
+   [securitygroup]
    firewall_driver = openvswitch
 
 OVN (ml2/ovn)
diff --git a/releasenotes/notes/fix-linuxbridge-secgroups-7e5cae9d630e3db9.yaml b/releasenotes/notes/fix-linuxbridge-secgroups-7e5cae9d630e3db9.yaml
new file mode 100644
index 0000000000..49fc9b6396
--- /dev/null
+++ b/releasenotes/notes/fix-linuxbridge-secgroups-7e5cae9d630e3db9.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fixes an issue with the Neutron Linux bridge ML2 driver where the firewall
+    driver configuration was not applied. `LP#1889455
+    <https://launchpad.net/bugs/1889455>`__