diff --git a/extensions/resteasy-reactive/rest-jaxb/deployment/src/test/java/io/quarkus/resteasy/reactive/jaxb/deployment/test/SimpleXmlTest.java b/extensions/resteasy-reactive/rest-jaxb/deployment/src/test/java/io/quarkus/resteasy/reactive/jaxb/deployment/test/SimpleXmlTest.java
index 4cfe409be76ff..b9ce38f92fc64 100644
--- a/extensions/resteasy-reactive/rest-jaxb/deployment/src/test/java/io/quarkus/resteasy/reactive/jaxb/deployment/test/SimpleXmlTest.java
+++ b/extensions/resteasy-reactive/rest-jaxb/deployment/src/test/java/io/quarkus/resteasy/reactive/jaxb/deployment/test/SimpleXmlTest.java
@@ -75,6 +75,17 @@ public void testXml() {
         assertEquals(person.getLast(), secondPerson.getLast());
     }
 
+    @Test
+    public void testInvalidXml() {
+        RestAssured
+                .with()
+                .body("<person><first>Bob</first></invalid>")
+                .contentType("application/xml")
+                .post("/simple/person")
+                .then()
+                .statusCode(400);
+    }
+
     @Test
     public void testLargeXmlPost() {
         StringBuilder sb = new StringBuilder();
diff --git a/extensions/resteasy-reactive/rest-jaxb/runtime/src/main/java/io/quarkus/resteasy/reactive/jaxb/runtime/serialisers/ServerJaxbMessageBodyReader.java b/extensions/resteasy-reactive/rest-jaxb/runtime/src/main/java/io/quarkus/resteasy/reactive/jaxb/runtime/serialisers/ServerJaxbMessageBodyReader.java
index 6a8226fba6d03..ab833016c9bc7 100644
--- a/extensions/resteasy-reactive/rest-jaxb/runtime/src/main/java/io/quarkus/resteasy/reactive/jaxb/runtime/serialisers/ServerJaxbMessageBodyReader.java
+++ b/extensions/resteasy-reactive/rest-jaxb/runtime/src/main/java/io/quarkus/resteasy/reactive/jaxb/runtime/serialisers/ServerJaxbMessageBodyReader.java
@@ -12,10 +12,12 @@
 import jakarta.ws.rs.core.Context;
 import jakarta.ws.rs.core.MediaType;
 import jakarta.ws.rs.core.MultivaluedMap;
+import jakarta.ws.rs.core.Response;
 import jakarta.ws.rs.ext.Providers;
 import jakarta.xml.bind.JAXBContext;
 import jakarta.xml.bind.JAXBElement;
 import jakarta.xml.bind.JAXBException;
+import jakarta.xml.bind.UnmarshalException;
 import jakarta.xml.bind.Unmarshaller;
 
 import org.jboss.resteasy.reactive.common.util.StreamUtil;
@@ -73,6 +75,8 @@ protected Object unmarshal(InputStream entityStream, Class<Object> type) {
             JAXBElement<Object> item = getUnmarshall(type)
                     .unmarshal(new StreamSource(entityStream), type);
             return item.getValue();
+        } catch (UnmarshalException e) {
+            throw new WebApplicationException(e, Response.Status.BAD_REQUEST);
         } catch (JAXBException e) {
             throw new RuntimeException(e);
         }