diff --git a/extensions/azure-functions/deployment/pom.xml b/extensions/azure-functions/deployment/pom.xml
index 10437cac5561b..f01b722b1d4d1 100644
--- a/extensions/azure-functions/deployment/pom.xml
+++ b/extensions/azure-functions/deployment/pom.xml
@@ -132,9 +132,6 @@
                                     <version>${project.version}</version>
                                 </path>
                             </annotationProcessorPaths>
-                            <compilerArgs>
-                                <arg>-AlegacyConfigRoot=true</arg>
-                            </compilerArgs>
                         </configuration>
                     </execution>
                 </executions>
diff --git a/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsConfig.java b/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsConfig.java
index b2994e55bd132..75e3954f397cf 100644
--- a/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsConfig.java
+++ b/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsConfig.java
@@ -9,7 +9,6 @@
 import java.util.Properties;
 
 import org.apache.commons.lang3.StringUtils;
-import org.jboss.logging.Logger;
 
 import com.azure.core.management.AzureEnvironment;
 import com.microsoft.azure.toolkit.lib.Azure;
@@ -31,27 +30,29 @@
 import io.quarkus.runtime.annotations.ConfigItem;
 import io.quarkus.runtime.annotations.ConfigPhase;
 import io.quarkus.runtime.annotations.ConfigRoot;
+import io.smallrye.config.ConfigMapping;
+import io.smallrye.config.WithDefault;
 
 /**
  * Azure Functions configuration.
  * Most options supported and name similarly to azure-functions-maven-plugin config
  */
 @ConfigRoot(phase = ConfigPhase.BUILD_TIME)
-public class AzureFunctionsConfig {
+@ConfigMapping(prefix = "quarkus.azure-functions")
+public interface AzureFunctionsConfig {
 
     /**
      * App name for azure function project. This is required setting.
      *
      * Defaults to the base artifact name
      */
-    @ConfigItem
-    public Optional<String> appName;
+    Optional<String> appName();
 
     /**
      * Azure Resource Group for your Azure Functions
      */
-    @ConfigItem(defaultValue = "quarkus")
-    public String resourceGroup;
+    @WithDefault("quarkus")
+    String resourceGroup();
 
     /**
      * Specifies the region where your Azure Functions will be hosted; default value is westus.
@@ -59,114 +60,105 @@ public class AzureFunctionsConfig {
      * "https://github.com/microsoft/azure-maven-plugins/wiki/Azure-Functions:-Configuration-Details#supported-regions">Valid
      * values</a>
      */
-    @ConfigItem(defaultValue = "westus")
-    public String region;
+    @WithDefault("westus")
+    String region();
 
     /**
      * Specifies whether to disable application insights for your function app
      */
-    @ConfigItem(defaultValue = "false")
-    public boolean disableAppInsights;
+    @WithDefault("false")
+    boolean disableAppInsights();
 
     /**
      * Specifies the instrumentation key of application insights which will bind to your function app
      */
-    @ConfigItem
-    public Optional<String> appInsightsKey;
+    Optional<String> appInsightsKey();
 
-    public RuntimeConfig runtime;
+    RuntimeConfig runtime();
 
-    public AuthConfig auth;
+    AuthConfig auth();
 
     /**
      * Specifies the name of the existing App Service Plan when you do not want to create a new one.
      */
-    @ConfigItem(defaultValue = "java-functions-app-service-plan")
-    public String appServicePlanName;
+    @WithDefault("java-functions-app-service-plan")
+    String appServicePlanName();
 
     /**
      * The app service plan resource group.
      */
-    @ConfigItem
-    public Optional<String> appServicePlanResourceGroup;
+    Optional<String> appServicePlanResourceGroup();
 
     /**
      * Azure subscription id. Required only if there are more than one subscription in your account
      */
-    @ConfigItem
-    public Optional<String> subscriptionId;
+    Optional<String> subscriptionId();
 
     /**
      * The pricing tier.
      */
-    @ConfigItem
-    public Optional<String> pricingTier;
+    Optional<String> pricingTier();
 
     /**
      * Port to run azure function in local runtime.
      * Will default to quarkus.http.test-port or 8081
      */
-    @ConfigItem
-    public Optional<Integer> funcPort;
+    Optional<Integer> funcPort();
 
     /**
      * Config String for local debug
      */
-    @ConfigItem(defaultValue = "transport=dt_socket,server=y,suspend=n,address=5005")
-    public String localDebugConfig;
+    @WithDefault("transport=dt_socket,server=y,suspend=n,address=5005")
+    String localDebugConfig();
 
     /**
      * Specifies the application settings for your Azure Functions, which are defined in name-value pairs
      */
     @ConfigItem
     @ConfigDocMapKey("setting-name")
-    public Map<String, String> appSettings = Collections.emptyMap();
+    Map<String, String> appSettings = Collections.emptyMap();
 
     @ConfigGroup
-    public static class RuntimeConfig {
+    interface RuntimeConfig {
         /**
          * Valid values are linux, windows, and docker
          */
-        @ConfigItem(defaultValue = "linux")
-        public String os;
+        @WithDefault("linux")
+        String os();
 
         /**
          * Valid values are 8, 11, and 17
          */
-        @ConfigItem(defaultValue = "11")
-        public String javaVersion;
+        @WithDefault("11")
+        String javaVersion();
 
         /**
          * URL of docker image if deploying via docker
          */
-        @ConfigItem
-        public Optional<String> image;
+        Optional<String> image();
 
         /**
          * If using docker, url of registry
          */
-        @ConfigItem
-        public Optional<String> registryUrl;
+        Optional<String> registryUrl();
 
     }
 
-    public FunctionAppConfig toFunctionAppConfig(String subscriptionId, String appName) {
+    default FunctionAppConfig toFunctionAppConfig(String subscriptionId, String appName) {
         Map<String, String> appSettings = this.appSettings;
         if (appSettings.isEmpty()) {
             appSettings = new HashMap<>();
             appSettings.put("FUNCTIONS_EXTENSION_VERSION", "~4");
         }
         return (FunctionAppConfig) new FunctionAppConfig()
-                .disableAppInsights(disableAppInsights)
-                .appInsightsKey(appInsightsKey.orElse(null))
-                .appInsightsInstance(appInsightsKey.orElse(null))
+                .disableAppInsights(disableAppInsights())
+                .appInsightsKey(appInsightsKey().orElse(null))
+                .appInsightsInstance(appInsightsKey().orElse(null))
                 .subscriptionId(subscriptionId)
-                .resourceGroup(resourceGroup)
+                .resourceGroup(resourceGroup())
                 .appName(appName)
-                .servicePlanName(appServicePlanName)
-                .servicePlanResourceGroup(appServicePlanResourceGroup.orElse(null))
-                //.deploymentSlotName(getDeploymentSlotName())
-                //.deploymentSlotConfigurationSource(getDeploymentSlotConfigurationSource())
+                .servicePlanName(appServicePlanName())
+                .servicePlanResourceGroup(appServicePlanResourceGroup().orElse(null))
                 .pricingTier(getParsedPricingTier(subscriptionId))
                 .region(getParsedRegion())
                 .runtime(getRuntimeConfig(subscriptionId))
@@ -174,42 +166,42 @@ public FunctionAppConfig toFunctionAppConfig(String subscriptionId, String appNa
     }
 
     private PricingTier getParsedPricingTier(String subscriptionId) {
-        return Optional.ofNullable(this.pricingTier.orElse(null)).map(PricingTier::fromString)
+        return Optional.ofNullable(this.pricingTier().orElse(null)).map(PricingTier::fromString)
                 .orElseGet(() -> Optional.ofNullable(getServicePlan(subscriptionId)).map(AppServicePlan::getPricingTier)
                         .orElse(null));
     }
 
     private AppServicePlan getServicePlan(String subscriptionId) {
-        final String servicePlan = this.appServicePlanName;
-        final String servicePlanGroup = StringUtils.firstNonBlank(this.appServicePlanResourceGroup.orElse(null),
-                this.resourceGroup);
+        final String servicePlan = this.appServicePlanName();
+        final String servicePlanGroup = StringUtils.firstNonBlank(this.appServicePlanResourceGroup().orElse(null),
+                this.resourceGroup());
         return StringUtils.isAnyBlank(subscriptionId, servicePlan, servicePlanGroup) ? null
                 : Azure.az(AzureAppService.class).plans(subscriptionId).get(servicePlan, servicePlanGroup);
     }
 
     private com.microsoft.azure.toolkit.lib.appservice.config.RuntimeConfig getRuntimeConfig(String subscriptionId) {
-        final RuntimeConfig runtime = this.runtime;
+        final RuntimeConfig runtime = this.runtime();
         if (runtime == null) {
             return null;
         }
-        final OperatingSystem os = Optional.ofNullable(runtime.os).map(OperatingSystem::fromString)
+        final OperatingSystem os = Optional.ofNullable(runtime.os()).map(OperatingSystem::fromString)
                 .orElseGet(
                         () -> Optional.ofNullable(getServicePlan(subscriptionId)).map(AppServicePlan::getOperatingSystem)
                                 .orElse(null));
-        final JavaVersion javaVersion = Optional.ofNullable(runtime.javaVersion).map(JavaVersion::fromString).orElse(null);
+        final JavaVersion javaVersion = Optional.ofNullable(runtime.javaVersion()).map(JavaVersion::fromString).orElse(null);
         final com.microsoft.azure.toolkit.lib.appservice.config.RuntimeConfig result = new com.microsoft.azure.toolkit.lib.appservice.config.RuntimeConfig()
                 .os(os)
                 .javaVersion(javaVersion).webContainer(WebContainer.JAVA_OFF)
-                .image(runtime.image.orElse(null)).registryUrl(runtime.registryUrl.orElse(null));
+                .image(runtime.image().orElse(null)).registryUrl(runtime.registryUrl().orElse(null));
         return result;
     }
 
     private Region getParsedRegion() {
-        return Optional.ofNullable(region).map(Region::fromName).orElse(null);
+        return Optional.ofNullable(region()).map(Region::fromName).orElse(null);
     }
 
     @ConfigGroup
-    public static class AuthConfig {
+    interface AuthConfig {
 
         /**
          * Description of each type can be found
@@ -234,28 +226,23 @@ public static class AuthConfig {
          *
          * Defaults to "azure_cli" for authentication
          */
-        @ConfigItem(defaultValue = "azure_cli")
-        public String type;
+        @WithDefault("azure_cli")
+        String type();
 
         /**
          * Filesystem path to properties file if using <i>file</i> type
          */
-        @ConfigItem
-        public Optional<String> path;
+        Optional<String> path();
 
         /**
          * Client or App Id required if using <i>managed_identity</i> type
          */
-        @ConfigItem
-        public Optional<String> client;
+        Optional<String> client();
 
         /**
-         * Tenant Id required if using <i>oauth2</i> or <i>device_code</i> type
+         * Tenant ID required if using <i>oauth2</i> or <i>device_code</i> type
          */
-        @ConfigItem
-        public Optional<String> tenant;
-
-        private static final Logger log = Logger.getLogger(AzureFunctionsConfig.class);
+        Optional<String> tenant();
 
         private static String findValue(Properties props, String key) {
             if (props.contains(key))
@@ -301,15 +288,15 @@ private static AuthConfiguration fromFile(Optional<String> path) {
             }
         }
 
-        public AuthConfiguration toAuthConfiguration() {
+        default AuthConfiguration toAuthConfiguration() {
             try {
-                if (this.type.equalsIgnoreCase("file")) {
-                    return fromFile(this.path);
+                if (this.type().equalsIgnoreCase("file")) {
+                    return fromFile(this.path());
                 }
-                final AuthType type = AuthType.parseAuthType(this.type);
+                final AuthType type = AuthType.parseAuthType(this.type());
                 final AuthConfiguration authConfiguration = new AuthConfiguration(type);
-                authConfiguration.setClient(client.orElse(null));
-                authConfiguration.setTenant(tenant.orElse(null));
+                authConfiguration.setClient(client().orElse(null));
+                authConfiguration.setTenant(tenant().orElse(null));
                 authConfiguration.setEnvironment(AzureEnvironmentUtils.azureEnvironmentToString(AzureEnvironment.AZURE));
                 return authConfiguration;
             } catch (InvalidConfigurationException e) {
diff --git a/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsDeployCommand.java b/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsDeployCommand.java
index aff10a43c92f2..544240480aead 100644
--- a/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsDeployCommand.java
+++ b/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsDeployCommand.java
@@ -167,22 +167,22 @@ protected void validateParameters(AzureFunctionsConfig config, String appName) t
             throw new BuildException(INVALID_APP_NAME);
         }
         // resource group
-        if (StringUtils.isBlank(config.resourceGroup)) {
+        if (StringUtils.isBlank(config.resourceGroup())) {
             throw new BuildException(EMPTY_RESOURCE_GROUP);
         }
-        if (config.resourceGroup.endsWith(".") || !config.resourceGroup.matches(RESOURCE_GROUP_PATTERN)) {
+        if (config.resourceGroup().endsWith(".") || !config.resourceGroup().matches(RESOURCE_GROUP_PATTERN)) {
             throw new BuildException(INVALID_RESOURCE_GROUP_NAME);
         }
         // asp name & resource group
-        if (StringUtils.isNotEmpty(config.appServicePlanName)
-                && !config.appServicePlanName.matches(APP_SERVICE_PLAN_NAME_PATTERN)) {
+        if (StringUtils.isNotEmpty(config.appServicePlanName())
+                && !config.appServicePlanName().matches(APP_SERVICE_PLAN_NAME_PATTERN)) {
             throw new BuildException(String.format(INVALID_SERVICE_PLAN_NAME, APP_SERVICE_PLAN_NAME_PATTERN));
         }
-        if (config.appServicePlanResourceGroup.isPresent()
-                && StringUtils.isNotEmpty(config.appServicePlanResourceGroup.orElse(null))
+        if (config.appServicePlanResourceGroup().isPresent()
+                && StringUtils.isNotEmpty(config.appServicePlanResourceGroup().orElse(null))
                 &&
-                (config.appServicePlanResourceGroup.orElse(null).endsWith(".")
-                        || !config.appServicePlanResourceGroup.orElse(null).matches(RESOURCE_GROUP_PATTERN))) {
+                (config.appServicePlanResourceGroup().orElse(null).endsWith(".")
+                        || !config.appServicePlanResourceGroup().orElse(null).matches(RESOURCE_GROUP_PATTERN))) {
             throw new BuildException(INVALID_SERVICE_PLAN_RESOURCE_GROUP_NAME);
         }
         // slot name
@@ -196,26 +196,26 @@ protected void validateParameters(AzureFunctionsConfig config, String appName) t
          *
          */
         // region
-        if (StringUtils.isNotEmpty(config.region) && Region.fromName(config.region).isExpandedValue()) {
-            log.warn(String.format(EXPANDABLE_REGION_WARNING, config.region));
+        if (StringUtils.isNotEmpty(config.region()) && Region.fromName(config.region()).isExpandedValue()) {
+            log.warn(String.format(EXPANDABLE_REGION_WARNING, config.region()));
         }
         // os
-        if (StringUtils.isNotEmpty(config.runtime.os) && OperatingSystem.fromString(config.runtime.os) == null) {
+        if (StringUtils.isNotEmpty(config.runtime().os()) && OperatingSystem.fromString(config.runtime().os()) == null) {
             throw new BuildException(INVALID_OS);
         }
         // java version
-        if (StringUtils.isNotEmpty(config.runtime.javaVersion)
-                && JavaVersion.fromString(config.runtime.javaVersion).isExpandedValue()) {
-            log.warn(String.format(EXPANDABLE_JAVA_VERSION_WARNING, config.runtime.javaVersion));
+        if (StringUtils.isNotEmpty(config.runtime().javaVersion())
+                && JavaVersion.fromString(config.runtime().javaVersion()).isExpandedValue()) {
+            log.warn(String.format(EXPANDABLE_JAVA_VERSION_WARNING, config.runtime().javaVersion()));
         }
         // pricing tier
-        if (config.pricingTier.isPresent() && StringUtils.isNotEmpty(config.pricingTier.orElse(null))
-                && PricingTier.fromString(config.pricingTier.orElse(null)).isExpandedValue()) {
-            log.warn(String.format(EXPANDABLE_PRICING_TIER_WARNING, config.pricingTier.orElse(null)));
+        if (config.pricingTier().isPresent() && StringUtils.isNotEmpty(config.pricingTier().orElse(null))
+                && PricingTier.fromString(config.pricingTier().orElse(null)).isExpandedValue()) {
+            log.warn(String.format(EXPANDABLE_PRICING_TIER_WARNING, config.pricingTier().orElse(null)));
         }
         // docker image
-        if (OperatingSystem.fromString(config.runtime.os) == OperatingSystem.DOCKER
-                && StringUtils.isEmpty(config.runtime.image.orElse(null))) {
+        if (OperatingSystem.fromString(config.runtime().os()) == OperatingSystem.DOCKER
+                && StringUtils.isEmpty(config.runtime().image().orElse(null))) {
             throw new BuildException(EMPTY_IMAGE_NAME);
         }
     }
@@ -226,9 +226,9 @@ protected void validateParameters(AzureFunctionsConfig config, String appName) t
 
     protected AzureAppService initAzureAppServiceClient(AzureFunctionsConfig config) throws BuildException {
         if (appServiceClient == null) {
-            final Account account = loginAzure(config.auth);
+            final Account account = loginAzure(config.auth());
             final List<Subscription> subscriptions = account.getSubscriptions();
-            final String targetSubscriptionId = getTargetSubscriptionId(config.subscriptionId.orElse(null), subscriptions,
+            final String targetSubscriptionId = getTargetSubscriptionId(config.subscriptionId().orElse(null), subscriptions,
                     account.getSelectedSubscriptions());
             checkSubscription(subscriptions, targetSubscriptionId);
             com.microsoft.azure.toolkit.lib.Azure.az(AzureAccount.class).account()
diff --git a/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsProcessor.java b/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsProcessor.java
index 04ef96151d917..438d5a70fe8f6 100644
--- a/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsProcessor.java
+++ b/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsProcessor.java
@@ -71,7 +71,7 @@ FeatureBuildItem feature() {
 
     @BuildStep
     AzureFunctionsAppNameBuildItem appName(OutputTargetBuildItem output, AzureFunctionsConfig functionsConfig) {
-        String appName = functionsConfig.appName.orElse(output.getBaseName());
+        String appName = functionsConfig.appName().orElse(output.getBaseName());
         return new AzureFunctionsAppNameBuildItem(appName);
     }
 
diff --git a/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsRunCommand.java b/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsRunCommand.java
index 7797fd7b49901..890e08a6f7ec5 100644
--- a/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsRunCommand.java
+++ b/extensions/azure-functions/deployment/src/main/java/io/quarkus/azure/functions/deployment/AzureFunctionsRunCommand.java
@@ -77,15 +77,15 @@ protected String getCheckRuntimeCommand() {
 
     protected String getStartFunctionHostCommand(AzureFunctionsConfig azureConfig) {
         int funcPort;
-        if (azureConfig.funcPort.isPresent()) {
-            funcPort = azureConfig.funcPort.get();
+        if (azureConfig.funcPort().isPresent()) {
+            funcPort = azureConfig.funcPort().get();
         } else {
             Config config = ConfigProviderResolver.instance().getConfig();
             funcPort = config.getValue("quarkus.http.test-port", OptionalInt.class).orElse(8081);
         }
         final String enableDebug = System.getProperty("enableDebug");
         if (StringUtils.isNotEmpty(enableDebug) && enableDebug.equalsIgnoreCase("true")) {
-            return String.format(FUNC_HOST_START_WITH_DEBUG_CMD, funcPort, azureConfig.localDebugConfig);
+            return String.format(FUNC_HOST_START_WITH_DEBUG_CMD, funcPort, azureConfig.localDebugConfig());
         } else {
             return String.format(FUNC_HOST_START_CMD, funcPort);
         }
diff --git a/extensions/azure-functions/runtime/pom.xml b/extensions/azure-functions/runtime/pom.xml
index 5440764ba4778..0901929c5192b 100644
--- a/extensions/azure-functions/runtime/pom.xml
+++ b/extensions/azure-functions/runtime/pom.xml
@@ -53,9 +53,6 @@
                                     <version>${project.version}</version>
                                 </path>
                             </annotationProcessorPaths>
-                            <compilerArgs>
-                                <arg>-AlegacyConfigRoot=true</arg>
-                            </compilerArgs>
                         </configuration>
                     </execution>
                 </executions>