diff --git a/independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/handlers/MediaTypeMapper.java b/independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/handlers/MediaTypeMapper.java
index 054febcab4d5c..79780144bb854 100644
--- a/independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/handlers/MediaTypeMapper.java
+++ b/independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/handlers/MediaTypeMapper.java
@@ -58,15 +58,11 @@ public MediaTypeMapper(List<RuntimeResource> runtimeResources) {
 
     @Override
     public void handle(ResteasyReactiveRequestContext requestContext) throws Exception {
-        String contentType = requestContext.serverRequest().getRequestHeader(HttpHeaders.CONTENT_TYPE);
-        // if there's no Content-Type it's */*
-        MediaType contentMediaType = contentType != null ? MediaType.valueOf(contentType) : MediaType.WILDCARD_TYPE;
         // find the best matching consumes type. Note that the arguments are reversed from their definition
         // of desired/provided, but we do want the result to be a media type we consume, since that's how we key
         // our methods, rather than the single media type we get from the client. This way we ensure we get the
         // best match.
-        MediaType consumes = MediaTypeHelper.getBestMatch(Collections.singletonList(contentMediaType),
-                consumesTypes);
+        MediaType consumes = MediaTypeHelper.getBestMatch(contentTypeFromRequest(requestContext), consumesTypes);
         Holder selectedHolder = resourcesByConsumes.get(consumes);
         // if we haven't found anything, try selecting the wildcard type, if any
         if (selectedHolder == null) {
@@ -97,6 +93,18 @@ public void handle(ResteasyReactiveRequestContext requestContext) throws Excepti
         requestContext.restart(selectedResource);
     }
 
+    private List<MediaType> contentTypeFromRequest(ResteasyReactiveRequestContext requestContext) {
+        List<String> contentTypeList = requestContext.getHttpHeaders().getRequestHeader(HttpHeaders.CONTENT_TYPE);
+        if (contentTypeList.isEmpty()) {
+            return Collections.singletonList(MediaType.WILDCARD_TYPE);
+        }
+        List<MediaType> result = new ArrayList<>(contentTypeList.size());
+        for (String s : contentTypeList) {
+            result.add(MediaType.valueOf(s));
+        }
+        return result;
+    }
+
     public MediaType selectMediaType(ResteasyReactiveRequestContext requestContext, Holder holder) {
         MediaType selected = null;
         List<String> accepts = requestContext.getHttpHeaders().getRequestHeader(HttpHeaders.ACCEPT);
diff --git a/independent-projects/resteasy-reactive/server/vertx/src/test/java/org/jboss/resteasy/reactive/server/vertx/test/matching/PreMatchContentTypeInHeaderTest.java b/independent-projects/resteasy-reactive/server/vertx/src/test/java/org/jboss/resteasy/reactive/server/vertx/test/matching/PreMatchContentTypeInHeaderTest.java
new file mode 100644
index 0000000000000..e17f34ad9c259
--- /dev/null
+++ b/independent-projects/resteasy-reactive/server/vertx/src/test/java/org/jboss/resteasy/reactive/server/vertx/test/matching/PreMatchContentTypeInHeaderTest.java
@@ -0,0 +1,114 @@
+package org.jboss.resteasy.reactive.server.vertx.test.matching;
+
+import static io.restassured.RestAssured.given;
+import static org.hamcrest.CoreMatchers.is;
+
+import java.io.IOException;
+import java.util.function.Supplier;
+
+import jakarta.ws.rs.Consumes;
+import jakarta.ws.rs.POST;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.container.ContainerRequestContext;
+import jakarta.ws.rs.container.ContainerRequestFilter;
+import jakarta.ws.rs.container.PreMatching;
+import jakarta.ws.rs.core.MediaType;
+import jakarta.ws.rs.ext.Provider;
+
+import org.jboss.resteasy.reactive.server.vertx.test.framework.ResteasyReactiveUnitTest;
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.spec.JavaArchive;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+public class PreMatchContentTypeInHeaderTest {
+
+    @RegisterExtension
+    static ResteasyReactiveUnitTest test = new ResteasyReactiveUnitTest()
+            .setArchiveProducer(new Supplier<>() {
+                @Override
+                public JavaArchive get() {
+                    return ShrinkWrap.create(JavaArchive.class);
+                }
+            });
+
+    @Test
+    public void filterNotSettingContentType() {
+        given()
+                .header("Content-Type", "application/json")
+                .body("[]")
+                .when()
+                .post("/test")
+                .then()
+                .statusCode(200)
+                .body(is("json-[]"));
+
+        given()
+                .header("Content-Type", "text/plain")
+                .body("input")
+                .when()
+                .post("/test")
+                .then()
+                .statusCode(200)
+                .body(is("text-input"));
+    }
+
+    @Test
+    public void filterSettingContentTypeToText() {
+        given()
+                .header("Content-Type", "application/json")
+                .header("test-content-type", "text/plain")
+                .body("[]")
+                .when()
+                .post("/test")
+                .then()
+                .statusCode(200)
+                .body(is("text-[]"));
+    }
+
+    @Test
+    public void filterSettingContentTypeToJson() {
+        given()
+                .header("Content-Type", "text/plain")
+                .header("test-content-type", "application/json")
+                .body("input")
+                .when()
+                .post("/test")
+                .then()
+                .statusCode(200)
+                .body(is("json-input"));
+    }
+
+    @Path("test")
+    public static class TestResource {
+
+        @POST
+        @Consumes(MediaType.TEXT_PLAIN)
+        public String fromText(String input) {
+            return "text-" + input;
+        }
+
+        @POST
+        @Consumes(MediaType.APPLICATION_JSON)
+        public String fromJson(String input) {
+            return "json-" + input;
+        }
+    }
+
+    public record Result(String message) {
+
+    }
+
+    @Provider
+    @PreMatching
+    public static class Filter implements ContainerRequestFilter {
+
+        @Override
+        public void filter(ContainerRequestContext context) throws IOException {
+            String testContentType = context.getHeaderString("test-content-type");
+            if (testContentType != null) {
+                context.getHeaders().putSingle("Content-Type", testContentType);
+            }
+        }
+    }
+}