diff --git a/http/http-advanced-reactive/src/main/java/io/quarkus/ts/http/advanced/reactive/CustomHeaderResponse.java b/http/http-advanced-reactive/src/main/java/io/quarkus/ts/http/advanced/reactive/CustomHeaderResponse.java
new file mode 100644
index 000000000..6db2a053e
--- /dev/null
+++ b/http/http-advanced-reactive/src/main/java/io/quarkus/ts/http/advanced/reactive/CustomHeaderResponse.java
@@ -0,0 +1,13 @@
+package io.quarkus.ts.http.advanced.reactive;
+
+public class CustomHeaderResponse {
+    private final String content;
+
+    public CustomHeaderResponse(String content) {
+        this.content = content;
+    }
+
+    public String getContent() {
+        return content;
+    }
+}
diff --git a/http/http-advanced-reactive/src/main/java/io/quarkus/ts/http/advanced/reactive/HeadersMessageBodyWriter.java b/http/http-advanced-reactive/src/main/java/io/quarkus/ts/http/advanced/reactive/HeadersMessageBodyWriter.java
new file mode 100644
index 000000000..3e78f71a8
--- /dev/null
+++ b/http/http-advanced-reactive/src/main/java/io/quarkus/ts/http/advanced/reactive/HeadersMessageBodyWriter.java
@@ -0,0 +1,29 @@
+package io.quarkus.ts.http.advanced.reactive;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Type;
+
+import jakarta.ws.rs.WebApplicationException;
+import jakarta.ws.rs.core.MediaType;
+import jakarta.ws.rs.core.MultivaluedMap;
+import jakarta.ws.rs.ext.MessageBodyWriter;
+import jakarta.ws.rs.ext.Provider;
+
+@Provider
+public class HeadersMessageBodyWriter implements MessageBodyWriter<CustomHeaderResponse> {
+
+    @Override
+    public boolean isWriteable(Class aClass, Type type, Annotation[] annotations, MediaType mediaType) {
+        return CustomHeaderResponse.class.isAssignableFrom(aClass) && MediaType.TEXT_PLAIN_TYPE.isCompatible(mediaType);
+    }
+
+    @Override
+    public void writeTo(CustomHeaderResponse customHeaderResponse, Class<?> aClass, Type type, Annotation[] annotations,
+                        MediaType mediaType, MultivaluedMap<String, Object> multivaluedMap, OutputStream outputStream)
+            throws IOException, WebApplicationException {
+        final String content = "Headers response: " + customHeaderResponse.getContent();
+        outputStream.write(content.getBytes());
+    }
+}
diff --git a/http/http-advanced-reactive/src/main/java/io/quarkus/ts/http/advanced/reactive/HeadersResource.java b/http/http-advanced-reactive/src/main/java/io/quarkus/ts/http/advanced/reactive/HeadersResource.java
index 985646487..bdf5fd034 100644
--- a/http/http-advanced-reactive/src/main/java/io/quarkus/ts/http/advanced/reactive/HeadersResource.java
+++ b/http/http-advanced-reactive/src/main/java/io/quarkus/ts/http/advanced/reactive/HeadersResource.java
@@ -2,6 +2,8 @@
 
 import jakarta.ws.rs.GET;
 import jakarta.ws.rs.Path;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.core.MediaType;
 import jakarta.ws.rs.core.Response;
 
 import io.smallrye.mutiny.Uni;
@@ -28,4 +30,11 @@ public Uni<Response> headersOverride() {
         return Uni.createFrom().item(response);
     }
 
+    @GET
+    @Path("/no-accept")
+    @Produces(MediaType.TEXT_PLAIN)
+    public Uni<String> okHeaders() {
+        return Uni.createFrom().item("ok headers");
+    }
+
 }
diff --git a/http/http-advanced-reactive/src/test/java/io/quarkus/ts/http/advanced/reactive/BaseHttpAdvancedReactiveIT.java b/http/http-advanced-reactive/src/test/java/io/quarkus/ts/http/advanced/reactive/BaseHttpAdvancedReactiveIT.java
index fd8f9168a..df954181b 100644
--- a/http/http-advanced-reactive/src/test/java/io/quarkus/ts/http/advanced/reactive/BaseHttpAdvancedReactiveIT.java
+++ b/http/http-advanced-reactive/src/test/java/io/quarkus/ts/http/advanced/reactive/BaseHttpAdvancedReactiveIT.java
@@ -98,7 +98,12 @@ public void httpServer() {
     @Test
     @DisplayName("GRPC Server test")
     public void testGrpc() {
-        getApp().given().when().get("/api/grpc/trinity").then().statusCode(SC_OK).body(is("Hello trinity"));
+        getApp().given()
+                .when()
+                .get("/api/grpc/trinity")
+                .then()
+                .statusCode(SC_OK)
+                .body(is("Hello trinity"));
     }
 
     @Test
diff --git a/http/http-advanced-reactive/src/test/java/io/quarkus/ts/http/advanced/reactive/DevModeGrpcIntegrationReactiveIT.java b/http/http-advanced-reactive/src/test/java/io/quarkus/ts/http/advanced/reactive/DevModeGrpcIntegrationReactiveIT.java
index 9517aae89..364a00055 100644
--- a/http/http-advanced-reactive/src/test/java/io/quarkus/ts/http/advanced/reactive/DevModeGrpcIntegrationReactiveIT.java
+++ b/http/http-advanced-reactive/src/test/java/io/quarkus/ts/http/advanced/reactive/DevModeGrpcIntegrationReactiveIT.java
@@ -70,7 +70,12 @@ public void testGrpcAsClient() throws ExecutionException, InterruptedException {
 
     @Test
     public void testGrpcViaRest() {
-        app.given().when().get("/api/grpc/trinity").then().statusCode(HttpStatus.SC_OK).body(is("Hello trinity"));
+        app.given()
+                .when()
+                .get("/api/grpc/trinity")
+                .then()
+                .statusCode(HttpStatus.SC_OK)
+                .body(is("Hello trinity"));
     }
 
     @Test
diff --git a/http/http-advanced-reactive/src/test/java/io/quarkus/ts/http/advanced/reactive/HeadersIT.java b/http/http-advanced-reactive/src/test/java/io/quarkus/ts/http/advanced/reactive/HeadersIT.java
index 5be721a99..1b158412d 100644
--- a/http/http-advanced-reactive/src/test/java/io/quarkus/ts/http/advanced/reactive/HeadersIT.java
+++ b/http/http-advanced-reactive/src/test/java/io/quarkus/ts/http/advanced/reactive/HeadersIT.java
@@ -10,6 +10,8 @@
 
 import java.util.List;
 
+import io.restassured.http.Header;
+import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Tag;
 import org.junit.jupiter.api.Test;
 
@@ -22,6 +24,8 @@
 public class HeadersIT {
 
     @QuarkusApplication(classes = { PathSpecificHeadersResource.class,
+            HeadersMessageBodyWriter.class,
+            CustomHeaderResponse.class,
             HeadersResource.class }, properties = "headers.properties")
     static RestService app = new RestService();
 
@@ -100,6 +104,20 @@ private ValidatableResponse whenGet(String path) {
                 .body(is("ok"));
     }
 
+    @Disabled("https://github.com/quarkusio/quarkus/issues/42854")
+    @Test
+    @Tag("https://github.com/quarkusio/quarkus/pull/41411")
+    void testWithNoAcceptHeader() {
+        Header header = new Header("Accept", null);
+        given()
+                .when()
+                .header(header)
+                .get("/headers/no-accept")
+                .then()
+                .statusCode(200)
+                .body(is("Headers response: ok headers"));
+    }
+
     /**
      * Cache-Control header may be present multiple times in the response, e.g. in an OpenShift deployment. That is why we need
      * to look for a specific value among all headers of the same name, and not just match the last one of them, which is what
diff --git a/http/http-advanced/src/main/java/io/quarkus/ts/http/advanced/CustomHeaderResponse.java b/http/http-advanced/src/main/java/io/quarkus/ts/http/advanced/CustomHeaderResponse.java
new file mode 100644
index 000000000..d6a21773b
--- /dev/null
+++ b/http/http-advanced/src/main/java/io/quarkus/ts/http/advanced/CustomHeaderResponse.java
@@ -0,0 +1,14 @@
+package io.quarkus.ts.http.advanced;
+
+public class CustomHeaderResponse {
+
+    private final String content;
+
+    public CustomHeaderResponse(String content) {
+        this.content = content;
+    }
+
+    public String getContent() {
+        return content;
+    }
+}
diff --git a/http/http-advanced/src/main/java/io/quarkus/ts/http/advanced/HeadersMessageBodyWriter.java b/http/http-advanced/src/main/java/io/quarkus/ts/http/advanced/HeadersMessageBodyWriter.java
new file mode 100644
index 000000000..b3cbbb8fc
--- /dev/null
+++ b/http/http-advanced/src/main/java/io/quarkus/ts/http/advanced/HeadersMessageBodyWriter.java
@@ -0,0 +1,29 @@
+package io.quarkus.ts.http.advanced;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Type;
+
+import jakarta.ws.rs.WebApplicationException;
+import jakarta.ws.rs.core.MediaType;
+import jakarta.ws.rs.core.MultivaluedMap;
+import jakarta.ws.rs.ext.MessageBodyWriter;
+import jakarta.ws.rs.ext.Provider;
+
+@Provider
+public class HeadersMessageBodyWriter implements MessageBodyWriter<CustomHeaderResponse> {
+
+    @Override
+    public boolean isWriteable(Class aClass, Type type, Annotation[] annotations, MediaType mediaType) {
+        return CustomHeaderResponse.class.isAssignableFrom(aClass) && MediaType.TEXT_PLAIN_TYPE.isCompatible(mediaType);
+    }
+
+    @Override
+    public void writeTo(CustomHeaderResponse customHeaderResponse, Class<?> aClass, Type type, Annotation[] annotations,
+            MediaType mediaType, MultivaluedMap<String, Object> multivaluedMap, OutputStream outputStream)
+            throws IOException, WebApplicationException {
+        final String content = "Headers response: " + customHeaderResponse.getContent();
+        outputStream.write(content.getBytes());
+    }
+}
diff --git a/http/http-advanced/src/main/java/io/quarkus/ts/http/advanced/HeadersResource.java b/http/http-advanced/src/main/java/io/quarkus/ts/http/advanced/HeadersResource.java
index 64d8aeadd..e9cf956b8 100644
--- a/http/http-advanced/src/main/java/io/quarkus/ts/http/advanced/HeadersResource.java
+++ b/http/http-advanced/src/main/java/io/quarkus/ts/http/advanced/HeadersResource.java
@@ -2,6 +2,8 @@
 
 import jakarta.ws.rs.GET;
 import jakarta.ws.rs.Path;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.core.MediaType;
 import jakarta.ws.rs.core.Response;
 
 @Path("/headers")
@@ -13,6 +15,13 @@ public String headers() {
         return "ok";
     }
 
+    @GET
+    @Path("/no-accept")
+    @Produces(MediaType.TEXT_PLAIN)
+    public CustomHeaderResponse noAcceptheaders() {
+        return new CustomHeaderResponse("ok");
+    }
+
     @GET
     @Path("/pragma")
     public String pragmaHeaderMustBeSet() {
diff --git a/http/http-advanced/src/test/java/io/quarkus/ts/http/advanced/BaseHttpAdvancedIT.java b/http/http-advanced/src/test/java/io/quarkus/ts/http/advanced/BaseHttpAdvancedIT.java
index df22cdc50..4f34bb95d 100644
--- a/http/http-advanced/src/test/java/io/quarkus/ts/http/advanced/BaseHttpAdvancedIT.java
+++ b/http/http-advanced/src/test/java/io/quarkus/ts/http/advanced/BaseHttpAdvancedIT.java
@@ -111,7 +111,13 @@ public void clientHostAddress(TestInfo testInfo) {
     @Test
     @DisplayName("GRPC Server test")
     public void testGrpc() {
-        getApp().given().when().get("/api/grpc/trinity").then().statusCode(HttpStatus.SC_OK).body(is("Hello trinity"));
+        getApp()
+                .given()
+                .when()
+                .get("/api/grpc/trinity")
+                .then()
+                .statusCode(HttpStatus.SC_OK)
+                .body(is("Hello trinity"));
     }
 
     @Test
diff --git a/http/http-advanced/src/test/java/io/quarkus/ts/http/advanced/DevModeGrpcIntegrationIT.java b/http/http-advanced/src/test/java/io/quarkus/ts/http/advanced/DevModeGrpcIntegrationIT.java
index 7a3d5b323..cf0581de0 100644
--- a/http/http-advanced/src/test/java/io/quarkus/ts/http/advanced/DevModeGrpcIntegrationIT.java
+++ b/http/http-advanced/src/test/java/io/quarkus/ts/http/advanced/DevModeGrpcIntegrationIT.java
@@ -68,7 +68,12 @@ public void testGrpcAsClient() {
 
     @Test
     public void testGrpcViaRest() {
-        app.given().when().get("/api/grpc/trinity").then().statusCode(HttpStatus.SC_OK).body(is("Hello trinity"));
+        app.given()
+                .when()
+                .get("/api/grpc/trinity")
+                .then()
+                .statusCode(HttpStatus.SC_OK)
+                .body(is("Hello trinity"));
     }
 
     @Test
diff --git a/http/http-advanced/src/test/java/io/quarkus/ts/http/advanced/HeadersIT.java b/http/http-advanced/src/test/java/io/quarkus/ts/http/advanced/HeadersIT.java
index 741d94622..8f928d0ad 100644
--- a/http/http-advanced/src/test/java/io/quarkus/ts/http/advanced/HeadersIT.java
+++ b/http/http-advanced/src/test/java/io/quarkus/ts/http/advanced/HeadersIT.java
@@ -16,12 +16,15 @@
 import io.quarkus.test.bootstrap.RestService;
 import io.quarkus.test.scenarios.QuarkusScenario;
 import io.quarkus.test.services.QuarkusApplication;
+import io.restassured.http.Header;
 import io.restassured.response.ValidatableResponse;
 
 @QuarkusScenario
 public class HeadersIT {
 
     @QuarkusApplication(classes = { PathSpecificHeadersResource.class,
+            HeadersMessageBodyWriter.class,
+            CustomHeaderResponse.class,
             HeadersResource.class }, properties = "headers.properties")
     static RestService app = new RestService();
 
@@ -93,6 +96,19 @@ void testPathSpecificHeaderRulesOrder() {
         cacheControlMatches(response, "max-age=1");
     }
 
+    @Test
+    @Tag("https://github.com/quarkusio/quarkus/pull/41411")
+    void testWithNoAcceptHeader() {
+        Header header = new Header("Accept", null);
+        given()
+                .when()
+                .header(header)
+                .get("/headers/no-accept")
+                .then()
+                .statusCode(200)
+                .body(is("Headers response: ok"));
+    }
+
     private ValidatableResponse whenGet(String path) {
         return given()
                 .get(path)