diff --git a/extensions/kubernetes-client/runtime/src/main/java/io/quarkus/kubernetes/client/runtime/KubernetesClientBuildConfig.java b/extensions/kubernetes-client/runtime/src/main/java/io/quarkus/kubernetes/client/runtime/KubernetesClientBuildConfig.java
index 1ceeac6447f6b1..bc97f1f9368350 100644
--- a/extensions/kubernetes-client/runtime/src/main/java/io/quarkus/kubernetes/client/runtime/KubernetesClientBuildConfig.java
+++ b/extensions/kubernetes-client/runtime/src/main/java/io/quarkus/kubernetes/client/runtime/KubernetesClientBuildConfig.java
@@ -2,6 +2,7 @@
 
 import java.time.Duration;
 import java.util.List;
+import java.util.Optional;
 
 import io.quarkus.runtime.annotations.ConfigItem;
 import io.quarkus.runtime.annotations.ConfigPhase;
@@ -20,73 +21,73 @@ public class KubernetesClientBuildConfig {
      * URL of the Kubernetes API server
      */
     @ConfigItem
-    String masterUrl;
+    Optional<String> masterUrl;
 
     /**
      * Default namespace to use
      */
     @ConfigItem
-    String namespace;
+    Optional<String> namespace;
 
     /**
      * CA certificate file
      */
     @ConfigItem
-    String caCertFile;
+    Optional<String> caCertFile;
 
     /**
      * CA certificate data
      */
     @ConfigItem
-    String caCertData;
+    Optional<String> caCertData;
 
     /**
      * Client certificate file
      */
     @ConfigItem
-    String clientCertFile;
+    Optional<String> clientCertFile;
 
     /**
      * Client certificate data
      */
     @ConfigItem
-    String clientCertData;
+    Optional<String> clientCertData;
 
     /**
      * Client key file
      */
     @ConfigItem
-    String clientKeyFile;
+    Optional<String> clientKeyFile;
 
     /**
      * Client key data
      */
     @ConfigItem
-    String clientKeyData;
+    Optional<String> clientKeyData;
 
     /**
      * Client key algorithm
      */
     @ConfigItem
-    String clientKeyAlgo;
+    Optional<String> clientKeyAlgo;
 
     /**
      * Client key passphrase
      */
     @ConfigItem
-    String clientKeyPassphrase;
+    Optional<String> clientKeyPassphrase;
 
     /**
      * Kubernetes auth username
      */
     @ConfigItem
-    String username;
+    Optional<String> username;
 
     /**
      * Kubernetes auth password
      */
     @ConfigItem
-    String password;
+    Optional<String> password;
 
     /**
      * Watch reconnect interval
@@ -123,29 +124,29 @@ public class KubernetesClientBuildConfig {
      * HTTP proxy used to access the Kubernetes API server
      */
     @ConfigItem
-    String httpProxy;
+    Optional<String> httpProxy;
 
     /**
      * HTTPS proxy used to access the Kubernetes API server
      */
     @ConfigItem
-    String httpsProxy;
+    Optional<String> httpsProxy;
 
     /**
      * Proxy username
      */
     @ConfigItem
-    String proxyUsername;
+    Optional<String> proxyUsername;
 
     /**
      * Proxy password
      */
     @ConfigItem
-    String proxyPassword;
+    Optional<String> proxyPassword;
 
     /**
      * IP addresses or hosts to exclude from proxying
      */
     @ConfigItem
-    List<String> noProxy;
+    List<Optional<String>> noProxy;
 }
diff --git a/extensions/kubernetes-client/runtime/src/main/java/io/quarkus/kubernetes/client/runtime/KubernetesClientProducer.java b/extensions/kubernetes-client/runtime/src/main/java/io/quarkus/kubernetes/client/runtime/KubernetesClientProducer.java
index 414444bc6e0d12..5ecb3798fc0fbb 100644
--- a/extensions/kubernetes-client/runtime/src/main/java/io/quarkus/kubernetes/client/runtime/KubernetesClientProducer.java
+++ b/extensions/kubernetes-client/runtime/src/main/java/io/quarkus/kubernetes/client/runtime/KubernetesClientProducer.java
@@ -27,22 +27,22 @@ public Config config() {
                 .withConnectionTimeout((int) buildConfig.connectionTimeout.toMillis())
                 .withRequestTimeout((int) buildConfig.requestTimeout.toMillis())
                 .withRollingTimeout(buildConfig.rollingTimeout.toMillis())
-                .withMasterUrl(or(buildConfig.masterUrl, base.getMasterUrl()))
-                .withNamespace(or(buildConfig.namespace, base.getNamespace()))
-                .withUsername(or(buildConfig.username, base.getUsername()))
-                .withPassword(or(buildConfig.password, base.getPassword()))
-                .withCaCertFile(or(buildConfig.caCertFile, base.getCaCertFile()))
-                .withCaCertData(or(buildConfig.caCertData, base.getCaCertData()))
-                .withClientCertFile(or(buildConfig.clientCertFile, base.getCaCertFile()))
-                .withClientCertData(or(buildConfig.clientCertData, base.getCaCertData()))
-                .withClientKeyFile(or(buildConfig.clientKeyFile, base.getClientKeyFile()))
-                .withClientKeyData(or(buildConfig.clientKeyData, base.getClientKeyData()))
-                .withClientKeyPassphrase(or(buildConfig.clientKeyPassphrase, base.getClientKeyPassphrase()))
-                .withClientKeyAlgo(or(buildConfig.clientKeyAlgo, base.getClientKeyAlgo()))
-                .withHttpProxy(or(buildConfig.httpProxy, base.getHttpProxy()))
-                .withHttpsProxy(or(buildConfig.httpsProxy, base.getHttpsProxy()))
-                .withProxyUsername(or(buildConfig.proxyUsername, base.getProxyUsername()))
-                .withProxyPassword(or(buildConfig.proxyPassword, base.getProxyPassword()))
+                .withMasterUrl(buildConfig.masterUrl.orElse(base.getMasterUrl()))
+                .withNamespace(buildConfig.namespace.orElse(base.getNamespace()))
+                .withUsername(buildConfig.username.orElse(base.getUsername()))
+                .withPassword(buildConfig.password.orElse(base.getPassword()))
+                .withCaCertFile(buildConfig.caCertFile.orElse(base.getCaCertFile()))
+                .withCaCertData(buildConfig.caCertData.orElse(base.getCaCertData()))
+                .withClientCertFile(buildConfig.clientCertFile.orElse(base.getCaCertFile()))
+                .withClientCertData(buildConfig.clientCertData.orElse(base.getCaCertData()))
+                .withClientKeyFile(buildConfig.clientKeyFile.orElse(base.getClientKeyFile()))
+                .withClientKeyData(buildConfig.clientKeyData.orElse(base.getClientKeyData()))
+                .withClientKeyPassphrase(buildConfig.clientKeyPassphrase.orElse(base.getClientKeyPassphrase()))
+                .withClientKeyAlgo(buildConfig.clientKeyAlgo.orElse(base.getClientKeyAlgo()))
+                .withHttpProxy(buildConfig.httpProxy.orElse(base.getHttpProxy()))
+                .withHttpsProxy(buildConfig.httpsProxy.orElse(base.getHttpsProxy()))
+                .withProxyUsername(buildConfig.proxyUsername.orElse(base.getProxyUsername()))
+                .withProxyPassword(buildConfig.proxyPassword.orElse(base.getProxyPassword()))
                 .withNoProxy(buildConfig.noProxy.size() > 0 ? buildConfig.noProxy.toArray(new String[0]) : base.getNoProxy())
                 .build();