diff --git a/napalm_opnsense/opnsense.py b/napalm_opnsense/opnsense.py
index c3276cc..9213903 100644
--- a/napalm_opnsense/opnsense.py
+++ b/napalm_opnsense/opnsense.py
@@ -2050,6 +2050,16 @@ class OPNsenseDriver(OPNsensePingMixin, FirewallDriver):
             "output": f"The update check did not finish within {_REFRESH_POLLS * _REFRESH_INTERVAL} s",
         }
 
+    def reboot_host(self) -> None:
+        """Restart the firewall through its firmware API (``HostRebootMixin``).
+
+        :raises RuntimeError: when the API refuses the request.
+        """
+        try:
+            self._post("/api/core/firmware/reboot")
+        except Exception as exc:
+            raise RuntimeError(f"The firewall refused to reboot: {exc}") from exc
+
     def get_host_status(self) -> dict[str, Any]:
         """Whether the firewall needs a reboot to finish an update; it does not
         patch itself as far as netOrk can tell."""
diff --git a/tests/unit/test_updates.py b/tests/unit/test_updates.py
index 9d82732..4f04b5a 100644
--- a/tests/unit/test_updates.py
+++ b/tests/unit/test_updates.py
@@ -123,3 +123,18 @@ class TestHostStatus:
     def test_no_pending_reboot(self, driver):
         with patch.object(driver, "_get", return_value=_status()):
             assert driver.get_host_status()["reboot_required"] is False
+
+
+class TestRebootHost:
+    """``reboot_host`` restarts the firewall through its firmware API (netOrk #637)."""
+
+    def test_the_firmware_api_is_asked(self, driver):
+        with patch.object(driver, "_post", return_value={"status": "ok"}) as post:
+            driver.reboot_host()
+
+        post.assert_called_once_with("/api/core/firmware/reboot")
+
+    def test_a_refusal_is_raised(self, driver):
+        with patch.object(driver, "_post", side_effect=ConnectionError("403 Forbidden")):
+            with pytest.raises(RuntimeError, match="403"):
+                driver.reboot_host()