diff --git a/extensions/resteasy-reactive/jaxrs-client-reactive/deployment/src/main/java/io/quarkus/jaxrs/client/reactive/deployment/ClientEndpointIndexer.java b/extensions/resteasy-reactive/jaxrs-client-reactive/deployment/src/main/java/io/quarkus/jaxrs/client/reactive/deployment/ClientEndpointIndexer.java
index 971df78e562ac..cedfbf44218ad 100644
--- a/extensions/resteasy-reactive/jaxrs-client-reactive/deployment/src/main/java/io/quarkus/jaxrs/client/reactive/deployment/ClientEndpointIndexer.java
+++ b/extensions/resteasy-reactive/jaxrs-client-reactive/deployment/src/main/java/io/quarkus/jaxrs/client/reactive/deployment/ClientEndpointIndexer.java
@@ -44,11 +44,13 @@ public class ClientEndpointIndexer
 
     private final String[] defaultProduces;
     private final String[] defaultProducesNegotiated;
+    private final boolean smartDefaultProduces;
 
-    ClientEndpointIndexer(Builder builder, String defaultProduces) {
+    ClientEndpointIndexer(Builder builder, String defaultProduces, boolean smartDefaultProduces) {
         super(builder);
         this.defaultProduces = new String[] { defaultProduces };
         this.defaultProducesNegotiated = new String[] { defaultProduces, MediaType.WILDCARD };
+        this.smartDefaultProduces = smartDefaultProduces;
     }
 
     public MaybeRestClientInterface createClientProxy(ClassInfo classInfo,
@@ -125,10 +127,14 @@ elementType, toClassName(paramType, currentClassInfo, actualEndpointInfo, index)
 
     @Override
     protected String[] applyAdditionalDefaults(Type nonAsyncReturnType) {
-        if (config.isSingleDefaultProduces()) {
-            return defaultProduces;
+        if (smartDefaultProduces) {
+            return super.applyAdditionalDefaults(nonAsyncReturnType);
         } else {
-            return defaultProducesNegotiated;
+            if (config.isSingleDefaultProduces()) {
+                return defaultProduces;
+            } else {
+                return defaultProducesNegotiated;
+            }
         }
     }
 
@@ -166,15 +172,21 @@ public static class ClientIndexedParam extends IndexedParameter<ClientIndexedPar
 
     public static final class Builder extends EndpointIndexer.Builder<ClientEndpointIndexer, Builder, ResourceMethod> {
         private String defaultProduces = MediaType.TEXT_PLAIN;
+        private boolean smartDefaultProduces = true;
 
         public Builder setDefaultProduces(String defaultProduces) {
             this.defaultProduces = defaultProduces;
             return this;
         }
 
+        public Builder setSmartDefaultProduces(boolean smartDefaultProduces) {
+            this.smartDefaultProduces = smartDefaultProduces;
+            return this;
+        }
+
         @Override
         public ClientEndpointIndexer build() {
-            return new ClientEndpointIndexer(this, defaultProduces);
+            return new ClientEndpointIndexer(this, defaultProduces, smartDefaultProduces);
         }
     }
 }
diff --git a/extensions/resteasy-reactive/jaxrs-client-reactive/deployment/src/main/java/io/quarkus/jaxrs/client/reactive/deployment/JaxrsClientReactiveProcessor.java b/extensions/resteasy-reactive/jaxrs-client-reactive/deployment/src/main/java/io/quarkus/jaxrs/client/reactive/deployment/JaxrsClientReactiveProcessor.java
index 4ebd6d3c9cfb1..3d1d3ee46949f 100644
--- a/extensions/resteasy-reactive/jaxrs-client-reactive/deployment/src/main/java/io/quarkus/jaxrs/client/reactive/deployment/JaxrsClientReactiveProcessor.java
+++ b/extensions/resteasy-reactive/jaxrs-client-reactive/deployment/src/main/java/io/quarkus/jaxrs/client/reactive/deployment/JaxrsClientReactiveProcessor.java
@@ -159,7 +159,8 @@ void setupClientProxies(JaxrsClientReactiveRecorder recorder,
             BuildProducer<GeneratedClassBuildItem> generatedClassBuildItemBuildProducer,
             BuildProducer<BytecodeTransformerBuildItem> bytecodeTransformerBuildItemBuildProducer,
             List<RestClientDefaultProducesBuildItem> defaultConsumes,
-            List<RestClientDefaultConsumesBuildItem> defaultProduces) {
+            List<RestClientDefaultConsumesBuildItem> defaultProduces,
+            List<RestClientDisableSmartDefaultProduces> disableSmartDefaultProduces) {
         String defaultConsumesType = defaultMediaType(defaultConsumes, MediaType.APPLICATION_OCTET_STREAM);
         String defaultProducesType = defaultMediaType(defaultProduces, MediaType.TEXT_PLAIN);
 
@@ -194,6 +195,7 @@ void setupClientProxies(JaxrsClientReactiveRecorder recorder,
                 .setDefaultBlocking(applicationResultBuildItem.getResult().isBlocking())
                 .setHasRuntimeConverters(false)
                 .setDefaultProduces(defaultProducesType)
+                .setSmartDefaultProduces(disableSmartDefaultProduces.isEmpty())
                 .build();
 
         Map<String, RuntimeValue<Function<WebTarget, ?>>> clientImplementations = new HashMap<>();
diff --git a/extensions/resteasy-reactive/jaxrs-client-reactive/deployment/src/main/java/io/quarkus/jaxrs/client/reactive/deployment/RestClientDisableSmartDefaultProduces.java b/extensions/resteasy-reactive/jaxrs-client-reactive/deployment/src/main/java/io/quarkus/jaxrs/client/reactive/deployment/RestClientDisableSmartDefaultProduces.java
new file mode 100644
index 0000000000000..ee0d6b162bfff
--- /dev/null
+++ b/extensions/resteasy-reactive/jaxrs-client-reactive/deployment/src/main/java/io/quarkus/jaxrs/client/reactive/deployment/RestClientDisableSmartDefaultProduces.java
@@ -0,0 +1,12 @@
+package io.quarkus.jaxrs.client.reactive.deployment;
+
+import io.quarkus.builder.item.MultiBuildItem;
+
+/**
+ * By default, RESTEasy Reactive uses text/plain content type for String values
+ * and application/json for everything else.
+ * MicroProfile Rest Client spec requires the implementations to always default to application/json.
+ * This build item disables the "smart" behavior of RESTEasy Reactive to comply to the spec
+ */
+public final class RestClientDisableSmartDefaultProduces extends MultiBuildItem {
+}
diff --git a/extensions/resteasy-reactive/rest-client-reactive/deployment/src/main/java/io/quarkus/rest/client/reactive/deployment/RestClientReactiveProcessor.java b/extensions/resteasy-reactive/rest-client-reactive/deployment/src/main/java/io/quarkus/rest/client/reactive/deployment/RestClientReactiveProcessor.java
index acd07d90a6ac7..8894a15c756b1 100644
--- a/extensions/resteasy-reactive/rest-client-reactive/deployment/src/main/java/io/quarkus/rest/client/reactive/deployment/RestClientReactiveProcessor.java
+++ b/extensions/resteasy-reactive/rest-client-reactive/deployment/src/main/java/io/quarkus/rest/client/reactive/deployment/RestClientReactiveProcessor.java
@@ -65,6 +65,7 @@
 import io.quarkus.jaxrs.client.reactive.deployment.JaxrsClientReactiveEnricherBuildItem;
 import io.quarkus.jaxrs.client.reactive.deployment.RestClientDefaultConsumesBuildItem;
 import io.quarkus.jaxrs.client.reactive.deployment.RestClientDefaultProducesBuildItem;
+import io.quarkus.jaxrs.client.reactive.deployment.RestClientDisableSmartDefaultProduces;
 import io.quarkus.rest.client.reactive.runtime.AnnotationRegisteredProviders;
 import io.quarkus.rest.client.reactive.runtime.HeaderCapturingServerFilter;
 import io.quarkus.rest.client.reactive.runtime.HeaderContainer;
@@ -98,9 +99,14 @@ ExtensionSslNativeSupportBuildItem activateSslNativeSupport() {
 
     @BuildStep
     void setUpDefaultMediaType(BuildProducer<RestClientDefaultConsumesBuildItem> consumes,
-            BuildProducer<RestClientDefaultProducesBuildItem> produces) {
+            BuildProducer<RestClientDefaultProducesBuildItem> produces,
+            BuildProducer<RestClientDisableSmartDefaultProduces> disableSmartProduces,
+            RestClientReactiveConfig config) {
         consumes.produce(new RestClientDefaultConsumesBuildItem(MediaType.APPLICATION_JSON, 10));
         produces.produce(new RestClientDefaultProducesBuildItem(MediaType.APPLICATION_JSON, 10));
+        if (config.disableSmartProduces) {
+            disableSmartProduces.produce(new RestClientDisableSmartDefaultProduces());
+        }
     }
 
     @BuildStep
diff --git a/extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/BasicMpRestClientTest.java b/extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/BasicRestClientTest.java
similarity index 97%
rename from extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/BasicMpRestClientTest.java
rename to extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/BasicRestClientTest.java
index 7703a3e52caf6..3e332a87d602b 100644
--- a/extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/BasicMpRestClientTest.java
+++ b/extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/BasicRestClientTest.java
@@ -18,7 +18,7 @@
 import io.quarkus.arc.Arc;
 import io.quarkus.test.QuarkusUnitTest;
 
-public class BasicMpRestClientTest {
+public class BasicRestClientTest {
     @RegisterExtension
     static final QuarkusUnitTest TEST = new QuarkusUnitTest()
             .setArchiveProducer(() -> ShrinkWrap.create(JavaArchive.class)
diff --git a/extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/HelloClient2.java b/extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/HelloClient2.java
index 4834c5cbb66a6..ab81bc507fb49 100644
--- a/extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/HelloClient2.java
+++ b/extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/HelloClient2.java
@@ -3,7 +3,6 @@
 import javax.ws.rs.Consumes;
 import javax.ws.rs.POST;
 import javax.ws.rs.Path;
-import javax.ws.rs.Produces;
 import javax.ws.rs.core.MediaType;
 
 import org.eclipse.microprofile.rest.client.inject.RegisterRestClient;
@@ -11,7 +10,6 @@
 @RegisterRestClient(configKey = "hello2")
 public interface HelloClient2 {
     @POST
-    @Produces(MediaType.TEXT_PLAIN)
     @Consumes(MediaType.TEXT_PLAIN)
     @Path("/")
     String echo(String name);
diff --git a/extensions/resteasy-reactive/rest-client-reactive/runtime/src/main/java/io/quarkus/rest/client/reactive/runtime/RestClientReactiveConfig.java b/extensions/resteasy-reactive/rest-client-reactive/runtime/src/main/java/io/quarkus/rest/client/reactive/runtime/RestClientReactiveConfig.java
index 642e05c388972..4dd42dd348918 100644
--- a/extensions/resteasy-reactive/rest-client-reactive/runtime/src/main/java/io/quarkus/rest/client/reactive/runtime/RestClientReactiveConfig.java
+++ b/extensions/resteasy-reactive/rest-client-reactive/runtime/src/main/java/io/quarkus/rest/client/reactive/runtime/RestClientReactiveConfig.java
@@ -8,8 +8,18 @@
 public class RestClientReactiveConfig {
 
     /**
-     * Default scope for MicroProfile Rest Client. Use `javax.enterprise.context.Dependent` for spec-compliant behavior
+     * Default scope for Rest Client Reactive. Use `javax.enterprise.context.Dependent` for spec-compliant behavior
      */
     @ConfigItem(name = "scope", defaultValue = "javax.enterprise.context.ApplicationScoped")
     public String scope;
+
+    /**
+     * By default, RESTEasy Reactive uses text/plain content type for String values
+     * and application/json for everything else.
+     *
+     * MicroProfile Rest Client spec requires the implementations to always default to application/json.
+     * This build item disables the "smart" behavior of RESTEasy Reactive to comply to the spec
+     */
+    @ConfigItem(name = "disable-smart-produces", defaultValue = "false")
+    public boolean disableSmartProduces;
 }
diff --git a/tcks/microprofile-rest-client-reactive/pom.xml b/tcks/microprofile-rest-client-reactive/pom.xml
index 56597e726a5d6..c8719dbcadd69 100644
--- a/tcks/microprofile-rest-client-reactive/pom.xml
+++ b/tcks/microprofile-rest-client-reactive/pom.xml
@@ -24,6 +24,7 @@
                         <io.quarkus.arquillian.copy-fields>true</io.quarkus.arquillian.copy-fields>
                         <quarkus.arc.remove-unused-beans>false</quarkus.arc.remove-unused-beans>
                         <quarkus.rest-client-reactive.scope>javax.enterprise.context.Dependent</quarkus.rest-client-reactive.scope>
+                        <quarkus.rest-client-reactive.disable-smart-produces>true</quarkus.rest-client-reactive.disable-smart-produces>
                         <vertx.disableTCCL>true</vertx.disableTCCL>
                         <wiremock.server.port>${wiremock.server.port}</wiremock.server.port>
                     </systemPropertyVariables>