diff --git a/src/DI/Resolver.php b/src/DI/Resolver.php
index da4d810d4..385df00a8 100644
--- a/src/DI/Resolver.php
+++ b/src/DI/Resolver.php
@@ -134,6 +134,9 @@ public function resolveEntityType(Statement $statement): ?string
 
 		} elseif (is_string($entity)) { // class
 			if (!class_exists($entity)) {
+				if (interface_exists($entity)) {
+					throw new ServiceCreationException("Interface '$entity' can not be used as 'factory', did you mean 'implement'?");
+				}
 				throw new ServiceCreationException("Class $entity not found.");
 			}
 			return $entity;