diff --git a/extensions/resteasy-reactive/quarkus-resteasy-reactive/deployment/src/main/java/io/quarkus/resteasy/reactive/server/deployment/ClassInjectorTransformer.java b/extensions/resteasy-reactive/quarkus-resteasy-reactive/deployment/src/main/java/io/quarkus/resteasy/reactive/server/deployment/ClassInjectorTransformer.java
index 8fa2ef6742dc5..2ede5c9c7ee64 100644
--- a/extensions/resteasy-reactive/quarkus-resteasy-reactive/deployment/src/main/java/io/quarkus/resteasy/reactive/server/deployment/ClassInjectorTransformer.java
+++ b/extensions/resteasy-reactive/quarkus-resteasy-reactive/deployment/src/main/java/io/quarkus/resteasy/reactive/server/deployment/ClassInjectorTransformer.java
@@ -296,7 +296,10 @@ private void generateConverterInitMethod(FieldInfo fieldInfo, ParameterConverter
 
         private ParameterConverterSupplier removeRuntimeResolvedConverterDelegate(ParameterConverterSupplier converter) {
             if (converter instanceof RuntimeResolvedConverter.Supplier) {
-                return ((RuntimeResolvedConverter.Supplier) converter).getDelegate();
+                ParameterConverterSupplier delegate = ((RuntimeResolvedConverter.Supplier) converter).getDelegate();
+                if (delegate != null) {
+                    return delegate;
+                }
             }
             return converter;
         }
diff --git a/extensions/resteasy-reactive/quarkus-resteasy-reactive/deployment/src/test/java/io/quarkus/resteasy/reactive/server/test/beanparam/CustomConverterInBeanParamTest.java b/extensions/resteasy-reactive/quarkus-resteasy-reactive/deployment/src/test/java/io/quarkus/resteasy/reactive/server/test/beanparam/CustomConverterInBeanParamTest.java
new file mode 100644
index 0000000000000..9573dcd9049c3
--- /dev/null
+++ b/extensions/resteasy-reactive/quarkus-resteasy-reactive/deployment/src/test/java/io/quarkus/resteasy/reactive/server/test/beanparam/CustomConverterInBeanParamTest.java
@@ -0,0 +1,98 @@
+package io.quarkus.resteasy.reactive.server.test.beanparam;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Type;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+
+import javax.ws.rs.BeanParam;
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.QueryParam;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.ext.ParamConverter;
+import javax.ws.rs.ext.ParamConverterProvider;
+import javax.ws.rs.ext.Provider;
+
+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;
+
+import io.quarkus.test.QuarkusUnitTest;
+import io.restassured.RestAssured;
+
+public class CustomConverterInBeanParamTest {
+
+    @RegisterExtension
+    static QuarkusUnitTest test = new QuarkusUnitTest()
+            .setArchiveProducer(() -> ShrinkWrap.create(JavaArchive.class)
+                    .addClasses(SearchResource.class, FilterData.class,
+                            JavaTimeParamConverterProvider.class, LocalDateTimeParamConverter.class));
+
+    @Test
+    void shouldCustomConvertBeUsedForLocalDateTimeInFilterData() {
+        LocalDateTime since = LocalDateTime.now();
+        String request = since.format(DateTimeFormatter.ISO_DATE_TIME);
+        String expected = since.plusYears(1).format(DateTimeFormatter.ISO_DATE_TIME);
+
+        RestAssured.get("/search?since=" + request)
+                .then()
+                .statusCode(200)
+                .body(equalTo("Got: " + expected));
+    }
+
+    @Path("/search")
+    public static class SearchResource {
+
+        @GET
+        @Produces(MediaType.TEXT_PLAIN)
+        public String search(@BeanParam FilterData filter) {
+            return "Got: " + filter.getSince().plusYears(1).format(DateTimeFormatter.ISO_DATE_TIME);
+        }
+    }
+
+    public static class FilterData {
+
+        @QueryParam("since")
+        private LocalDateTime since;
+
+        public LocalDateTime getSince() {
+            return since;
+        }
+
+        public void setSince(LocalDateTime since) {
+            this.since = since;
+        }
+    }
+
+    public static class LocalDateTimeParamConverter implements ParamConverter<LocalDateTime> {
+
+        @Override
+        public LocalDateTime fromString(String value) {
+            return LocalDateTime.parse(value, DateTimeFormatter.ISO_DATE_TIME);
+        }
+
+        @Override
+        public String toString(LocalDateTime value) {
+            return value.format(DateTimeFormatter.ISO_DATE_TIME);
+        }
+    }
+
+    @Provider
+    public static class JavaTimeParamConverterProvider implements ParamConverterProvider {
+
+        @Override
+        public <T> ParamConverter<T> getConverter(Class<T> rawType, Type genericType, Annotation[] annotations) {
+            if (rawType == LocalDateTime.class) {
+                return (ParamConverter<T>) new LocalDateTimeParamConverter();
+            }
+
+            return null;
+        }
+
+    }
+}