@@ -16,6 +16,7 @@
 import io.javaoperatorsdk.operator.api.config.ConfigurationServiceOverrider;
 import io.javaoperatorsdk.operator.api.config.ControllerConfiguration;
 import io.javaoperatorsdk.operator.api.config.ControllerConfigurationOverrider;
+import io.javaoperatorsdk.operator.api.config.UpdatableConfigurationService;
 import io.javaoperatorsdk.operator.api.reconciler.Reconciler;
 import io.javaoperatorsdk.operator.processing.Controller;
 import io.javaoperatorsdk.operator.processing.LifecycleAware;
@@ -26,7 +27,7 @@ public class Operator implements LifecycleAware {
 
 private final ControllerManager controllerManager;
 private final LeaderElectionManager leaderElectionManager;
-private final ConfigurationService configurationService;
+private final UpdatableConfigurationService configurationService;
 private volatile boolean started = false;
 
 public Operator() {
@@ -45,7 +46,7 @@ public Operator() {
 * @param configurationService a {@link ConfigurationService} providing the configuration for the
 * operator
 */
-public Operator(ConfigurationService configurationService) {
+public Operator(UpdatableConfigurationService configurationService) {
 this.configurationService = configurationService;
 
 final var executorServiceManager = configurationService.getExecutorServiceManager();
@@ -65,7 +66,7 @@ public Operator(Consumer<ConfigurationServiceOverrider> overrider) {
 this(initConfigurationService(null, overrider));
 }
 
-private static ConfigurationService initConfigurationService(
+private static UpdatableConfigurationService initConfigurationService(
 KubernetesClient client, Consumer<ConfigurationServiceOverrider> overrider) {
 // initialize the client if the user didn't provide one
 if (client == null) {
@@ -82,7 +83,7 @@ private static ConfigurationService initConfigurationService(
 overrider = o -> o.withKubernetesClient(kubernetesClient);
 }
 
-return ConfigurationService.newOverriddenConfigurationService(overrider);
+return UpdatableConfigurationService.newOverriddenConfigurationService(overrider);
 }
 
 /**
@@ -209,6 +210,12 @@ public <P extends HasMetadata> RegisteredController<P> register(
 + configurationService.getKnownReconcilerNames());
 }
 
+// update the reconciler's configuration in the ConfigurationService if needed
+final var existing = configurationService.getConfigurationFor(reconciler);
+if (!configuration.equals(existing)) {
+configurationService.replace(configuration);
+}
+
 final var controller = new Controller<>(reconciler, configuration, getKubernetesClient());
 
 controllerManager.add(controller);

@@ -14,7 +14,7 @@
 * An abstract implementation of {@link ConfigurationService} meant to ease custom implementations
 */
 @SuppressWarnings("rawtypes")
-public class AbstractConfigurationService implements ConfigurationService {
+public class AbstractConfigurationService implements UpdatableConfigurationService {
 private final Map<String, ControllerConfiguration> configurations = new ConcurrentHashMap<>();
 private final Version version;
 private KubernetesClient client;
@@ -71,15 +71,16 @@ public AbstractConfigurationService(
 protected void init(
 Cloner cloner, ExecutorServiceManager executorServiceManager, KubernetesClient client) {
 this.client = client;
-this.cloner = cloner != null ? cloner : ConfigurationService.super.getResourceCloner();
+this.cloner = cloner != null ? cloner : UpdatableConfigurationService.super.getResourceCloner();
 this.executorServiceManager = executorServiceManager;
 }
 
 protected <R extends HasMetadata> void register(ControllerConfiguration<R> config) {
 put(config, true);
 }
 
-protected <R extends HasMetadata> void replace(ControllerConfiguration<R> config) {
+@Override
+public <R extends HasMetadata> void replace(ControllerConfiguration<R> config) {
 put(config, false);
 }
 
@@ -162,7 +163,7 @@ public Cloner getResourceCloner() {
 public KubernetesClient getKubernetesClient() {
 // lazy init to avoid needing initializing a client when not needed (in tests, in particular)
 if (client == null) {
-client = ConfigurationService.super.getKubernetesClient();
+client = UpdatableConfigurationService.super.getKubernetesClient();
 }
 return client;
 }
@@ -171,7 +172,7 @@ public KubernetesClient getKubernetesClient() {
 public ExecutorServiceManager getExecutorServiceManager() {
 // lazy init to avoid initializing thread pools for nothing in an overriding scenario
 if (executorServiceManager == null) {
-executorServiceManager = ConfigurationService.super.getExecutorServiceManager();
+executorServiceManager = UpdatableConfigurationService.super.getExecutorServiceManager();
 }
 return executorServiceManager;
 }

@@ -0,0 +1,20 @@
+package io.javaoperatorsdk.operator.api.config;
+
+import java.util.function.Consumer;
+
+import io.fabric8.kubernetes.api.model.HasMetadata;
+
+public interface UpdatableConfigurationService extends ConfigurationService {
+<R extends HasMetadata> void replace(ControllerConfiguration<R> config);
+
+static UpdatableConfigurationService newOverriddenConfigurationService(
+Consumer<ConfigurationServiceOverrider> overrider) {
+final var baseConfiguration = new BaseConfigurationService();
+if (overrider != null) {
+final var toOverride = new ConfigurationServiceOverrider(baseConfiguration);
+overrider.accept(toOverride);
+return (UpdatableConfigurationService) toOverride.build();
+}
+return baseConfiguration;
+}
+}

@@ -1,5 +1,7 @@
 package io.javaoperatorsdk.operator;
 
+import java.util.Set;
+
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -51,6 +53,15 @@ void shouldBePossibleToRetrieveRegisteredControllerByName() {
 assertEquals(maybeController.get(), registeredControllers.stream().findFirst().orElseThrow());
 }
 
+@Test
+void overriddenConfigurationShouldBeUpdatedInConfigurationService() {
+final var reconciler = new FooReconciler();
+operator.register(new FooReconciler(), override -> override.settingNamespace("test"));
+final var config = operator.getConfigurationService().getConfigurationFor(reconciler);
+final var namespaces = config.getInformerConfig().getNamespaces();
+assertEquals(Set.of("test"), namespaces);
+}
+
 @ControllerConfiguration
 private static class FooReconciler implements Reconciler<ConfigMap> {