diff --git a/src/MetadataFactory.php b/src/MetadataFactory.php
index b2e02a2..08470b3 100644
--- a/src/MetadataFactory.php
+++ b/src/MetadataFactory.php
@@ -90,7 +90,11 @@ public function getMetadataForClass(string $className)
 
                 if (null !== $classMetadata) {
                     if (!$classMetadata instanceof ClassMetadata) {
-                        throw new \LogicException(sprintf('The cache must return instances of ClassMetadata, but got %s.', var_export($classMetadata, true)));
+                        throw new \LogicException(sprintf(
+                            'The cache must return instances of ClassMetadata for class %s, but got %s.',
+                            $className,
+                            var_export($classMetadata, true)
+                        ));
                     }
 
                     if ($this->debug && !$classMetadata->isFresh()) {