diff --git a/ironic_python_agent/extensions/standby.py b/ironic_python_agent/extensions/standby.py
index e0ed1d6c9..8d7c26c68 100644
--- a/ironic_python_agent/extensions/standby.py
+++ b/ironic_python_agent/extensions/standby.py
@@ -160,7 +160,7 @@ def _write_partition_image(image, image_info, device):
     preserve_ep = image_info['preserve_ephemeral']
     configdrive = image_info['configdrive']
     boot_option = image_info.get('boot_option', 'local')
-    boot_mode = image_info.get('deploy_boot_mode', 'bios')
+    boot_mode = utils.get_node_boot_mode(cached_node)
     disk_label = utils.get_partition_table_type_from_specs(cached_node)
     root_mb = image_info['root_mb']
 
diff --git a/ironic_python_agent/tests/unit/extensions/test_standby.py b/ironic_python_agent/tests/unit/extensions/test_standby.py
index 5fe7ca581..68b2c5d76 100644
--- a/ironic_python_agent/tests/unit/extensions/test_standby.py
+++ b/ironic_python_agent/tests/unit/extensions/test_standby.py
@@ -1364,6 +1364,7 @@ class TestStandbyExtension(base.IronicAgentTest):
         result = self.agent_extension.get_partition_uuids()
         self.assertEqual({'1': '2'}, result.serialize()['command_result'])
 
+    @mock.patch.object(utils, 'get_node_boot_mode', lambda self: 'uefi')
     @mock.patch.object(utils, 'get_partition_table_type_from_specs',
                        lambda self: 'gpt')
     @mock.patch.object(hardware, 'dispatch_to_managers', autospec=True)
@@ -1386,7 +1387,6 @@ class TestStandbyExtension(base.IronicAgentTest):
         node_uuid = image_info['node_uuid']
         pr_ep = image_info['preserve_ephemeral']
         configdrive = image_info['configdrive']
-        boot_mode = image_info['deploy_boot_mode']
         boot_option = image_info['boot_option']
         cpu_arch = self.fake_cpu.architecture
 
@@ -1408,7 +1408,7 @@ class TestStandbyExtension(base.IronicAgentTest):
                                                   node_uuid,
                                                   configdrive=configdrive,
                                                   preserve_ephemeral=pr_ep,
-                                                  boot_mode=boot_mode,
+                                                  boot_mode='uefi',
                                                   boot_option=boot_option,
                                                   disk_label='gpt',
                                                   cpu_arch=cpu_arch)
diff --git a/releasenotes/notes/fix-boot-mode-for-partition-images-f96cf2b3c27b6533.yaml b/releasenotes/notes/fix-boot-mode-for-partition-images-f96cf2b3c27b6533.yaml
new file mode 100644
index 000000000..b3d23ccf7
--- /dev/null
+++ b/releasenotes/notes/fix-boot-mode-for-partition-images-f96cf2b3c27b6533.yaml
@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    Fixes issue where the running system operating mode was not taken into
+    account when writing partition images. The agent now utilises a helper
+    instead of explicitly expecting the flavor derived information to
+    supply all deployment context.