diff --git a/extensions/resteasy-classic/rest-client-config/runtime/src/main/java/io/quarkus/restclient/config/RestClientsBuildTimeConfig.java b/extensions/resteasy-classic/rest-client-config/runtime/src/main/java/io/quarkus/restclient/config/RestClientsBuildTimeConfig.java
index e4caffdc8453f..f3aa7ead6abe7 100644
--- a/extensions/resteasy-classic/rest-client-config/runtime/src/main/java/io/quarkus/restclient/config/RestClientsBuildTimeConfig.java
+++ b/extensions/resteasy-classic/rest-client-config/runtime/src/main/java/io/quarkus/restclient/config/RestClientsBuildTimeConfig.java
@@ -83,10 +83,15 @@ interface RestClientBuildConfig {
      * @return a {@link RestClientsBuildTimeConfig} with the discovered registered REST Clients configuration only.
      */
     default RestClientsBuildTimeConfig get(List<RegisteredRestClient> restClients) {
-        SmallRyeConfig config = new SmallRyeConfigBuilder()
+        return getConfig(restClients).getConfigMapping(RestClientsBuildTimeConfig.class);
+    }
+
+    default SmallRyeConfig getConfig(List<RegisteredRestClient> restClients) {
+        return new SmallRyeConfigBuilder()
                 .withSources(
                         new ConfigSource() {
                             final SmallRyeConfig config = ConfigProvider.getConfig().unwrap(SmallRyeConfig.class);
+                            final ConfigSource defaultsSource = getDefaultsSource();
 
                             @Override
                             public Set<String> getPropertyNames() {
@@ -97,13 +102,25 @@ public Set<String> getPropertyNames() {
 
                             @Override
                             public String getValue(final String propertyName) {
-                                return config.getRawValue(propertyName);
+                                ConfigValue configValue = config.getConfigValue(propertyName);
+                                if (configValue != null && !defaultsSource.getName().equals(configValue.getSourceName())) {
+                                    return configValue.getValue();
+                                }
+                                return null;
                             }
 
                             @Override
                             public String getName() {
                                 return "SmallRye Config";
                             }
+
+                            private ConfigSource getDefaultsSource() {
+                                ConfigSource configSource = null;
+                                for (ConfigSource source : config.getConfigSources()) {
+                                    configSource = source;
+                                }
+                                return configSource;
+                            }
                         })
                 .withCustomizers(new SmallRyeConfigBuilderCustomizer() {
                     @Override
@@ -119,7 +136,5 @@ public List<RegisteredRestClient> getRestClients() {
                 .withMapping(RestClientsBuildTimeConfig.class)
                 .withMappingIgnore("quarkus.**")
                 .build();
-
-        return config.getConfigMapping(RestClientsBuildTimeConfig.class);
     }
 }
diff --git a/extensions/resteasy-classic/rest-client-config/runtime/src/test/java/io/quarkus/restclient/config/RestClientConfigTest.java b/extensions/resteasy-classic/rest-client-config/runtime/src/test/java/io/quarkus/restclient/config/RestClientConfigTest.java
index 8476badf6a4d2..2a8c2621726c5 100644
--- a/extensions/resteasy-classic/rest-client-config/runtime/src/test/java/io/quarkus/restclient/config/RestClientConfigTest.java
+++ b/extensions/resteasy-classic/rest-client-config/runtime/src/test/java/io/quarkus/restclient/config/RestClientConfigTest.java
@@ -2,6 +2,7 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -232,6 +233,19 @@ public List<RegisteredRestClient> getRestClients() {
         assertThat(restClientConfig.uri().get()).isEqualTo("http://localhost:8082");
     }
 
+    @Test
+    void buildTimeConfig() {
+        SmallRyeConfig config = ConfigUtils.emptyConfigBuilder()
+                .withMapping(RestClientsBuildTimeConfig.class)
+                .build();
+        assertNotNull(config);
+
+        RestClientsBuildTimeConfig buildTimeConfig = config.getConfigMapping(RestClientsBuildTimeConfig.class)
+                .get(List.of(new RegisteredRestClient(ConfigKeyRestClient.class, "key")));
+
+        assertFalse(buildTimeConfig.clients().get(ConfigKeyRestClient.class.getName()).removesTrailingSlash());
+    }
+
     private void verifyConfig(RestClientConfig config) {
         assertTrue(config.url().isPresent());
         assertThat(config.url().get()).isEqualTo("http://localhost:8080");
diff --git a/extensions/resteasy-reactive/rest-client/deployment/src/main/java/io/quarkus/rest/client/reactive/deployment/devservices/DevServicesRestClientHttpProxyProcessor.java b/extensions/resteasy-reactive/rest-client/deployment/src/main/java/io/quarkus/rest/client/reactive/deployment/devservices/DevServicesRestClientHttpProxyProcessor.java
index 913697d6af206..6e2eb61e3f12c 100644
--- a/extensions/resteasy-reactive/rest-client/deployment/src/main/java/io/quarkus/rest/client/reactive/deployment/devservices/DevServicesRestClientHttpProxyProcessor.java
+++ b/extensions/resteasy-reactive/rest-client/deployment/src/main/java/io/quarkus/rest/client/reactive/deployment/devservices/DevServicesRestClientHttpProxyProcessor.java
@@ -17,7 +17,6 @@
 import java.util.stream.Collectors;
 
 import org.apache.commons.lang3.exception.UncheckedException;
-import org.eclipse.microprofile.config.ConfigProvider;
 import org.jboss.jandex.ClassInfo;
 import org.jboss.jandex.IndexView;
 import org.jboss.logging.Logger;
@@ -32,6 +31,7 @@
 import io.quarkus.rest.client.reactive.deployment.RegisteredRestClientBuildItem;
 import io.quarkus.rest.client.reactive.spi.DevServicesRestClientProxyProvider;
 import io.quarkus.rest.client.reactive.spi.RestClientHttpProxyBuildItem;
+import io.quarkus.restclient.config.RegisteredRestClient;
 import io.quarkus.restclient.config.RestClientsBuildTimeConfig;
 import io.quarkus.restclient.config.RestClientsBuildTimeConfig.RestClientBuildConfig;
 import io.smallrye.config.SmallRyeConfig;
@@ -60,14 +60,15 @@ public void determineRequiredProxies(
             CombinedIndexBuildItem combinedIndexBuildItem,
             List<RegisteredRestClientBuildItem> registeredRestClientBuildItems,
             BuildProducer<RestClientHttpProxyBuildItem> producer) {
-        Map<String, RestClientBuildConfig> configs = clientsConfig.get(toRegisteredRestClients(registeredRestClientBuildItems))
-                .clients();
+
+        List<RegisteredRestClient> registeredRestClients = toRegisteredRestClients(registeredRestClientBuildItems);
+        Map<String, RestClientBuildConfig> configs = clientsConfig.get(registeredRestClients).clients();
         if (configs.isEmpty()) {
             return;
         }
 
         IndexView index = combinedIndexBuildItem.getIndex();
-        SmallRyeConfig config = ConfigProvider.getConfig().unwrap(SmallRyeConfig.class);
+        SmallRyeConfig config = clientsConfig.getConfig(registeredRestClients);
         for (var configEntry : configs.entrySet()) {
             if (!configEntry.getValue().enableLocalProxy()) {
                 log.trace("Ignoring config key: '" + configEntry.getKey() + "' because enableLocalProxy is false");