diff --git a/ironic/cmd/conductor.py b/ironic/cmd/conductor.py
index ecd1aa13ab..7d65d2514f 100644
--- a/ironic/cmd/conductor.py
+++ b/ironic/cmd/conductor.py
@@ -81,7 +81,7 @@ def main():
 
     profiler.setup('ironic_conductor', CONF.host)
 
-    launcher = service.launch(CONF, mgr)
+    launcher = service.launch(CONF, mgr, restart_method='mutate')
     launcher.wait()
 
 
diff --git a/ironic/common/service.py b/ironic/common/service.py
index a077889bb4..e0a8f1852d 100644
--- a/ironic/common/service.py
+++ b/ironic/common/service.py
@@ -36,4 +36,4 @@ def prepare_service(argv=None):
 
 
 def process_launcher():
-    return service.ProcessLauncher(CONF)
+    return service.ProcessLauncher(CONF, restart_method='mutate')
diff --git a/ironic/conf/default.py b/ironic/conf/default.py
index 6611b96889..e1c709d39b 100644
--- a/ironic/conf/default.py
+++ b/ironic/conf/default.py
@@ -282,7 +282,7 @@ service_opts = [
                       'hostname, FQDN, or IP address.')),
     cfg.StrOpt('pin_release_version',
                choices=versions.RELEASE_VERSIONS,
-               # TODO(xek): mutable=True,
+               mutable=True,
                help=_('Used for rolling upgrades. Setting this option '
                       'downgrades (or pins) the Bare Metal API, '
                       'the internal ironic RPC communication, and '
diff --git a/releasenotes/notes/sighup-service-reloads-configs-0e2462e3f064a2ff.yaml b/releasenotes/notes/sighup-service-reloads-configs-0e2462e3f064a2ff.yaml
new file mode 100644
index 0000000000..ac3058ccaa
--- /dev/null
+++ b/releasenotes/notes/sighup-service-reloads-configs-0e2462e3f064a2ff.yaml
@@ -0,0 +1,17 @@
+---
+features:
+  - |
+    Issuing a SIGHUP (e.g. ``pkill -HUP ironic``) to an ironic-api or
+    ironic-conductor service will cause the service to reload and use any
+    changed values for *mutable* configuration options. The mutable
+    configuration options are:
+
+    * [DEFAULT]/debug
+    * [DEFAULT]/log_config_append
+    * [DEFAULT]/pin_release_version
+
+    Mutable configuration options are indicated as such in the `sample configuration
+    file <https://docs.openstack.org/ironic/latest/configuration/sample-config.html>`_
+    by ``Note: This option can be changed without restarting``.
+
+    A warning is logged for any changes to immutable configuration options.