diff --git a/extensions/resteasy-reactive/rest-client-reactive/runtime/src/main/java/io/quarkus/rest/client/reactive/runtime/RestClientBuilderImpl.java b/extensions/resteasy-reactive/rest-client-reactive/runtime/src/main/java/io/quarkus/rest/client/reactive/runtime/RestClientBuilderImpl.java
index 657849440d32e..9e2bb6ace28be 100644
--- a/extensions/resteasy-reactive/rest-client-reactive/runtime/src/main/java/io/quarkus/rest/client/reactive/runtime/RestClientBuilderImpl.java
+++ b/extensions/resteasy-reactive/rest-client-reactive/runtime/src/main/java/io/quarkus/rest/client/reactive/runtime/RestClientBuilderImpl.java
@@ -319,7 +319,8 @@ public <T> T build(Class<T> aClass) throws IllegalStateException, RestClientDefi
 
         ArcContainer arcContainer = Arc.container();
         if (arcContainer == null) {
-            throw new IllegalStateException("The Reactive REST Client is not meant to be used outside of Quarkus");
+            throw new IllegalStateException(
+                    "The Reactive REST Client needs to be built within the context of a Quarkus application with a valid ArC (CDI) context running.");
         }
 
         RestClientListeners.get().forEach(listener -> listener.onNewClient(aClass, this));