diff --git a/config/main.py b/config/main.py
index 7cdea6fbc..556bba669 100644
--- a/config/main.py
+++ b/config/main.py
@@ -2200,6 +2200,24 @@ def reload(db, filename, yes, load_sysinfo, no_service_restart, force, file_form
             config_file_yang_validation(filename)
 
     #Stop services before config push
+    if not no_service_restart:
+        try:
+            _db = swsscommon.DBConnector('STATE_DB', 0)
+            boot_type = None
+            # fast-reboot sets both FAST_RESTART_ENABLE_TABLE and WARM_RESTART_ENABLE_TABLE;
+            # check fast first so the label is correct when both flags are set.
+            if swsscommon.RestartWaiter.isFastBootInProgress(_db):
+                boot_type = 'fast-reboot'
+            elif swsscommon.RestartWaiter.isWarmBootInProgress(_db):
+                boot_type = 'warm-boot'
+            if boot_type:
+                click.echo(f"A {boot_type} is still in progress. Please wait for finalization to complete.")
+                sys.exit(CONFIG_RELOAD_NOT_READY)
+        except SystemExit:
+            raise
+        except Exception:
+            pass
+
     if not no_service_restart:
         log.log_notice("'reload' stopping services...")
         _stop_services()
diff --git a/tests/config_test.py b/tests/config_test.py
index 5ffdb5edb..51b778b17 100644
--- a/tests/config_test.py
+++ b/tests/config_test.py
@@ -754,6 +754,90 @@ def test_config_reload(self, get_cmd_module, setup_single_broadcom_asic):
             assert "\n".join([line.rstrip() for line in result.output.split('\n')][:2]) == \
                 reload_config_with_sys_info_command_output.format(config.SYSTEM_RELOAD_LOCK)
 
+    def test_config_reload_blocked_during_warm_boot(self, get_cmd_module, setup_single_broadcom_asic):
+        """config reload must abort when a warm-boot is in progress (Redmine #5154490)."""
+        (config, show) = get_cmd_module
+        jsonfile_config = os.path.join(mock_db_path, "config_db.json")
+
+        mock_swsscommon = mock.MagicMock()
+        mock_swsscommon.RestartWaiter.isWarmBootInProgress.return_value = True
+        mock_swsscommon.RestartWaiter.isFastBootInProgress.return_value = False
+
+        with mock.patch.object(config, "DEFAULT_CONFIG_DB_FILE", jsonfile_config), \
+                mock.patch('config.main.swsscommon', mock_swsscommon), \
+                mock.patch('config.main._is_system_starting', return_value=False), \
+                mock.patch('config.main._swss_ready', return_value=True), \
+                mock.patch.object(config, 'config_file_yang_validation'):
+            result = CliRunner().invoke(config.config.commands["reload"], ["-y"])
+            assert result.exit_code != 0
+            assert "warm-boot" in result.output
+            assert "still in progress" in result.output
+
+    def test_config_reload_blocked_during_fast_boot(self, get_cmd_module, setup_single_broadcom_asic):
+        """config reload must abort when a fast-reboot is in progress.
+        fast-reboot sets both FAST_RESTART_ENABLE_TABLE and WARM_RESTART_ENABLE_TABLE;
+        isFastBootInProgress is checked first so the label is correct."""
+        (config, show) = get_cmd_module
+        jsonfile_config = os.path.join(mock_db_path, "config_db.json")
+
+        mock_swsscommon = mock.MagicMock()
+        mock_swsscommon.RestartWaiter.isWarmBootInProgress.return_value = True
+        mock_swsscommon.RestartWaiter.isFastBootInProgress.return_value = True
+
+        with mock.patch.object(config, "DEFAULT_CONFIG_DB_FILE", jsonfile_config), \
+                mock.patch('config.main.swsscommon', mock_swsscommon), \
+                mock.patch('config.main._is_system_starting', return_value=False), \
+                mock.patch('config.main._swss_ready', return_value=True), \
+                mock.patch.object(config, 'config_file_yang_validation'):
+            result = CliRunner().invoke(config.config.commands["reload"], ["-y"])
+            assert result.exit_code != 0
+            assert "fast-reboot" in result.output
+            assert "still in progress" in result.output
+
+    def test_config_reload_not_blocked_when_no_boot_in_progress(self, get_cmd_module, setup_single_broadcom_asic):
+        """Guard runs but does not block when no boot is in progress; both checks are invoked."""
+        (config, show) = get_cmd_module
+        jsonfile_config = os.path.join(mock_db_path, "config_db.json")
+
+        mock_swsscommon = mock.MagicMock()
+        mock_swsscommon.RestartWaiter.isWarmBootInProgress.return_value = False
+        mock_swsscommon.RestartWaiter.isFastBootInProgress.return_value = False
+
+        with mock.patch.object(config, "DEFAULT_CONFIG_DB_FILE", jsonfile_config), \
+                mock.patch('config.main.swsscommon', mock_swsscommon), \
+                mock.patch.object(config, 'config_file_yang_validation'), \
+                mock.patch('config.main._is_system_starting', return_value=False), \
+                mock.patch('config.main._swss_ready', return_value=True), \
+                mock.patch('config.main._stop_services'), \
+                mock.patch('config.main._restart_services'), \
+                mock.patch('config.main._reset_failed_services'), \
+                mock.patch("utilities_common.cli.run_command",
+                           mock.MagicMock(side_effect=mock_run_command_side_effect)):
+            result = CliRunner().invoke(config.config.commands["reload"], ["-y"])
+            assert result.exit_code == 0
+            assert "still in progress" not in result.output
+            mock_swsscommon.RestartWaiter.isFastBootInProgress.assert_called_once()
+            mock_swsscommon.RestartWaiter.isWarmBootInProgress.assert_called_once()
+
+    def test_config_reload_no_service_restart_skips_guard(self, get_cmd_module, setup_single_broadcom_asic):
+        """With -n (no_service_restart), guard is skipped — no syncd teardown, no risk."""
+        (config, show) = get_cmd_module
+        jsonfile_config = os.path.join(mock_db_path, "config_db.json")
+
+        mock_swsscommon = mock.MagicMock()
+        mock_swsscommon.RestartWaiter.isWarmBootInProgress.return_value = True
+
+        with mock.patch.object(config, "DEFAULT_CONFIG_DB_FILE", jsonfile_config), \
+                mock.patch('config.main.swsscommon', mock_swsscommon), \
+                mock.patch.object(config, 'config_file_yang_validation'), \
+                mock.patch("utilities_common.cli.run_command",
+                           mock.MagicMock(side_effect=mock_run_command_side_effect)):
+            result = CliRunner().invoke(config.config.commands["reload"], ["-y", "-n"])
+            assert result.exit_code == 0
+            assert "still in progress" not in result.output
+            mock_swsscommon.RestartWaiter.isFastBootInProgress.assert_not_called()
+            mock_swsscommon.RestartWaiter.isWarmBootInProgress.assert_not_called()
+
     def test_config_reload_stdin(self, get_cmd_module, setup_single_broadcom_asic):
         def mock_json_load(f):
             device_metadata = {